# D&D Extraction Module Refactoring Audit Strategy

Status: Strategy complete; final audit results recorded below

## Purpose

Define a disciplined audit of the five production D&D extraction modules:

- `dnd/spells`;
- `dnd/npcs`;
- `dnd/combat-turns`;
- `dnd/npc-interactions`; and
- `dnd/scene-descriptions`.

The audit will determine whether these modules follow a coherent set of
conventions, whether repeated implementation can be replaced by appropriately
scoped shared code or assets, and whether the accumulated design suggests other
maintainability improvements.

This document defines how to perform the audit. It does not contain audit
findings and does not authorize production changes.

## Audit Principles

The audit must distinguish consistency from uniformity. The five modules should
use the same conventions where they perform the same responsibility, but a
module should remain different when its artifact semantics, evidence model,
reference requirements, or normalization policy require it.

Recommendations must follow these principles:

- Prefer evidence from current code, tests, prompts, schemas, configuration,
  and documentation over naming or visual similarity.
- Treat a divergence as a finding only when it is unexplained, increases
  maintenance or correctness risk, or violates an intended convention.
- Do not recommend an abstraction solely to reduce line count. A shared helper
  must own one coherent invariant and make future correct changes easier.
- Preserve package ownership of artifact semantics, private response DTOs,
  private structured-output schemas, and lane-specific prompts.
- Keep D&D-specific behavior in D&D packages. Move behavior into a generic
  framework package only when the contract is demonstrably domain-neutral and
  has a non-D&D consumer or a clear framework-owned responsibility.
- Evaluate prompt sharing by byte identity and semantic ownership. Prompt
  caching benefits only when repeated message content and ordering are exactly
  identical.
- Apply the testing policy to proposed refactors. Prefer behavioral protection
  at stable boundaries and do not add change-detector tests for helper usage,
  prompt length, exact hashes, or private file layout.

## Scope

### Primary scope

Inspect the complete package-owned implementation beneath:

- `internal/modules/dnd/extract/spells`;
- `internal/modules/dnd/extract/npcs`;
- `internal/modules/dnd/extract/combatturns`;
- `internal/modules/dnd/extract/npcinteractions`; and
- `internal/modules/dnd/extract/scenedescriptions`.

For each package, include:

- module identity, capabilities, construction, options, registration, and
  execution class;
- reference-slot declarations and construction-time or operation-time
  reference handling;
- checkpoint fingerprints and manifest metadata;
- request validation and structured LLM request preparation;
- private response DTOs, response-schema loading, and response mapping;
- source-reference resolution, evidence attachment, canonicalization,
  ordering, and exact deduplication;
- embedded prompt manifests, shared and local assets, message order, cache
  boundaries, and schema assets;
- errors, warnings, diagnostics, cloning, and mutation safety; and
- package-local tests and test support.

### Contextual scope

Inspect a neighboring component only when needed to determine ownership,
duplication, or compatibility:

- `internal/modules/dnd/shared` and focused D&D subpackages used by more than
  one extractor;
- the five artifact model and codec contracts;
- corresponding merge, normalize, and validate variants;
- production registration and default validator composition;
- pipeline reference, fingerprint, and LLM contracts;
- canonical current-behavior documentation and integration contracts; and
- representative production and integration tests.

Contextual inspection is not a request to redesign every lane stage. Findings
outside extraction should be reported only when they directly explain an
extractor inconsistency or reveal a misplaced responsibility.

### Exclusions

Do not use this audit to:

- change durable artifact schemas or extraction policy;
- redesign the fixed pipeline shape or ordered-step model;
- combine distinct artifacts into a larger D&D result;
- evaluate live-model output quality;
- introduce schema generation, a dependency-injection framework, or a general
  module superclass;
- move domain rules into the generic framework;
- rewrite tests merely to make their file layout look alike; or
- implement any recommended refactor.

If the audit exposes a product-contract concern, record it separately from
refactoring recommendations and identify the additional decision required.

## Comparison Method

### 1. Establish a module inventory

Create one row per module in a working comparison matrix. Record exact current
facts rather than inferred conventions:

| Dimension | Facts to record |
| --- | --- |
| Identity | Module key, artifact kind, capabilities, execution class |
| Files | Production files, embedded assets, focused test files |
| Construction | Dependencies, options, reference decoding, immutable prepared state |
| Registration | `ModuleSpec`, builder, option validation, declared slots |
| Provenance | Manifest metadata and checkpoint fingerprint keys and values |
| Prompt | Prompt ID/version, manifest messages, inputs, shared assets, cache boundaries |
| Schema | Private schema identity, strictness, loader, diagnostics behavior |
| Execution | Request validation, LLM call, response mapping, errors and warnings |
| Evidence | Source identity, range resolution, canonicalization, ordering, deduplication |
| Tests | Contract owner, malformed cases, integration coverage, test-only helpers |

Use the matrix to identify exact agreement, intentional variation, and
unexplained variation. Do not infer a preferred convention from whichever
module was implemented first. Determine the preferred shape from architecture,
current documentation, shared contracts, and the clearest implementation.

### 2. Classify every divergence

Assign each observed difference one classification:

- **Required specialization:** the artifact or reference contract requires the
  difference. No harmonization is recommended.
- **Permitted variation:** implementations differ without meaningful
  maintenance or correctness cost.
- **Convention drift:** equivalent responsibilities use different names,
  layouts, error behavior, metadata, validation, or tests without a reason.
- **Architectural divergence:** responsibility is placed in the wrong layer or
  bypasses a shared contract.
- **Undetermined:** more evidence or a policy decision is needed.

For required specialization, document the reason briefly so a future audit
does not repeatedly flag it. For drift or architectural divergence, identify
the preferred convention and why it is preferable.

### 3. Build a duplication inventory

Search for three kinds of repetition:

1. **Exact duplication:** identical Go logic, prompt text, schema fragments, or
   test support.
2. **Structural duplication:** the same algorithm or lifecycle expressed with
   renamed domain types.
3. **Policy duplication:** the same invariant is independently encoded in
   several production or test layers.

Trace callers and consumers before recommending extraction. Record:

- the repeated responsibility;
- participating modules;
- meaningful semantic differences;
- change history or likely change cadence when discoverable;
- defect risk if copies drift;
- proposed owner and API shape; and
- code or assets that would remain module-owned.

Similar code is not sufficient evidence. Prefer a shared abstraction when at
least one of the following is true:

- three or more modules independently implement the same nontrivial invariant;
- two modules share correctness-sensitive behavior that must evolve together;
- existing duplicated code has already drifted or caused a defect; or
- an existing shared contract is being reimplemented locally.

Avoid extraction when the shared API would need artifact-specific callbacks,
large configuration objects, type erasure, or branching on module identity.
Those are signs that visual similarity is masking separate responsibilities.

## Convention Review

Evaluate the following conventions across all five modules.

### Package organization

- Comparable responsibilities use predictable filenames and package-local
  ownership.
- Optional specialized files, such as catalog or registry wiring, are present
  only where the module has that responsibility.
- Exported identifiers are limited to framework and registration contracts.
- Test helpers remain local unless sharing them improves test clarity without
  coupling independent suites.

### Construction and registration

- Required dependencies fail during construction.
- Options are decoded and unknown options rejected consistently.
- `ModuleSpec`, reference slots, artifact kind, execution class, and builder
  behavior agree with runtime behavior.
- Construction resolves stable reference-derived state where possible, while
  operation requests own genuinely run- or chunk-specific inputs.
- Returned specs, metadata, fingerprints, and byte slices have consistent
  defensive-copy behavior.

### Prompt and schema boundary

- Shared prompt messages come from canonical shared assets; package assets
  contain only lane-specific wording.
- Shared content is exactly identical across manifests and appears in the
  documented cache-friendly order.
- Stable messages and cache boundaries precede the variable transcript.
- Declared prompt inputs match reference slots and generated projections.
- Private response schemas are strict structural envelopes and reject unknown
  fields.
- Semantic validation remains in deterministic code at the intended boundary.
- Schema identity, version, digest, and diagnostics are exposed consistently
  without leaking schema or prompt content.

### Extraction and evidence

- Request validation and contextual error wrapping follow one recognizable
  pattern.
- Reference material aids disambiguation but never becomes transcript evidence.
- Source unit IDs are resolved against document order rather than numeric
  assumptions.
- Mapping performs only the deterministic transformations owned by extraction.
- Canonical source references, stable ordering, and exact deduplication use
  consistent policies where artifact semantics agree.
- Whole-chunk evidence in scene descriptions is treated as an intentional
  specialization rather than forced through citation-oriented helpers.
- Results do not share mutable state with model responses, references, or
  requests.

### Provenance and diagnostics

- Prompt and response-schema identities and hashes appear consistently in
  manifest metadata.
- Checkpoint fingerprints cover every stable semantic input that could change
  accepted output, without including credentials, paths, timestamps, or source
  content.
- Registry and catalog projections use canonical bytes and retain bounded
  provenance.
- Errors and diagnostics are contextual, bounded, and free of raw reference or
  secret content.

### Tests

- Each important contract has one clear test owner.
- Equivalent risks receive comparable coverage without requiring identical test
  file layouts.
- Schema tests cover required structure and unknown-field rejection without
  duplicating every semantic validator case.
- Extractor tests cover request validation, response mapping, evidence,
  ordering, references, and provider failures at the narrowest stable boundary.
- Prompt tests prepare real embedded assets and protect input placement,
  ordering, cache boundaries, and content-safety properties without freezing
  exact prompt text.
- Registration or production tests prove assembly once and do not repeat
  package-local behavior unnecessarily.
- Obsolete, redundant, representation-specific, or impossible fixtures are
  identified for deletion or simplification.

## Shared-Code Decision Framework

Recommend the narrowest owner that matches the repeated responsibility:

1. Keep artifact semantics in the module that owns the artifact.
2. Use `internal/modules/dnd/shared` for D&D-wide mechanics with identical
   semantics, such as prompt inputs or source-unit reference handling.
3. Use a focused D&D subpackage for behavior shared by a subset of lanes, such
   as NPC registry projection, when it has a coherent domain contract.
4. Use a framework package only for transport-neutral or domain-neutral
   behavior owned by the framework.

Evaluate these candidate categories without assuming they should be extracted:

- extractor request precondition validation;
- private response-schema loading and metadata assembly;
- prompt asset registration and hashing;
- source-reference conversion, canonical ordering, and exact deduplication;
- manifest metadata and checkpoint fingerprint assembly;
- NPC registry resolution and names-only projection;
- strict option decoding and module registration;
- diagnostic redaction and bounded error context; and
- repeated test fixtures or schema-validation utilities.

For prompts and schemas:

- Factor prompt wording into a shared asset only when every consumer needs the
  exact same text and should receive future changes atomically.
- Prefer an existing shared asset over a new near-duplicate.
- Do not create shared prompt fragments solely because prose is similar.
- Keep private response schemas package-owned unless a genuine shared wire
  contract exists.
- Do not introduce shared JSON Schema fragments or generation unless the audit
  demonstrates a maintenance problem that outweighs tooling and indirection.

## Additional Quality Review

Beyond consistency and duplication, inspect:

- functions with high cognitive complexity or responsibilities that can be
  separated without obscuring the extraction flow;
- repeated linear scans inside loops, avoidable serialization, unnecessary
  allocations, or per-chunk reconstruction of stable state;
- hidden mutation, aliasing, or inconsistent clone boundaries;
- fingerprint omissions that could permit stale checkpoint reuse;
- prompt inputs or references repeated unnecessarily across messages;
- unreachable defensive checks or validation performed redundantly at several
  layers;
- errors that lose module, field, source, or stage context;
- stale documentation, fixtures, names, compatibility aliases, or comments;
- public or package abstractions that have only one artificial consumer; and
- opportunities to delete code after a shared helper replaces it.

Performance recommendations must identify a plausible workload and complexity
impact. Do not recommend micro-optimization without evidence.

## Evidence Collection

Perform the audit in this order:

1. Read the architecture, testing, documentation, module, LLM, pipeline, and
   relevant integration contracts.
2. Build the five-module comparison matrix from definitions and assets.
3. Use graph similarity only to identify candidates; read the complete
   functions and trace their callers before classifying them.
4. Compare prompt manifests and shared assets byte-for-byte, then compare local
   prompt semantics.
5. Compare private schemas structurally and map each field to its DTO, mapper,
   durable artifact, and validator owner.
6. Trace reference and fingerprint data from construction through the LLM
   request and checkpoint identity.
7. Review focused tests alongside the behavior they own.
8. Run the existing focused and repository-wide validation commands to
   distinguish current failures from maintainability observations.

Do not modify production code, tests, prompts, schemas, examples, or
current-behavior documentation during the audit.

## Finding Standard

Every reported finding must contain:

- severity: high, medium, or low;
- category: convention drift, duplication, architecture, correctness,
  performance, testing, or documentation;
- affected modules and exact file or symbol references;
- observed behavior and the convention or invariant it is compared against;
- concrete maintenance, correctness, cost, or security impact;
- recommended target state and ownership;
- why the recommendation is preferable to leaving the code separate; and
- validation or migration considerations.

Order findings by severity and impact, not by module. Separate confirmed
findings from optional improvements. State explicitly when no issue is found in
a comparison area.

For each apparent duplication, the audit must choose one outcome:

- extract now;
- harmonize without sharing;
- retain intentionally separate; or
- defer pending a named missing requirement.

Do not report speculative abstractions as findings. Record them, if useful, as
rejected or deferred candidates with the reason.

## Audit Deliverable

The completed audit should provide:

1. an executive conclusion addressing convention consistency, shared-code
   opportunities, and overall code quality;
2. the completed five-module comparison matrix;
3. prioritized findings with evidence and recommendations;
4. intentional differences that should be preserved;
5. rejected or deferred sharing candidates and rationale;
6. a proposed refactoring sequence grouped into independently safe changes;
   and
7. validation commands and any residual risks.

The audit should be actionable enough to support a later decision-complete
implementation plan, but it must not implement or silently commit any
recommendation.

## Completion Criteria

The strategy has been followed when:

- all five primary packages and their prompts, schemas, registration,
  provenance, reference handling, mapping, and tests have been compared;
- every divergence has a classification;
- every repeated candidate has an ownership and keep/share decision;
- architecture and testing-policy constraints are applied explicitly;
- findings cite exact evidence and explain impact;
- intentional specialization is documented alongside drift;
- repository validation results are recorded; and
- no production changes were made as part of the audit.

## Audit Results

Status: Complete

### Executive Conclusion

The five D&D extraction modules follow a coherent overall convention: all are
typed, production-registered extractors with strict private response schemas,
package-owned artifact mapping, bounded provenance, shared canonical prompt
assets, defensive result ownership, and deterministic downstream validation.
Their differences in catalog/registry state, reference slots, local prompt
assets, whole-chunk versus cited evidence, and scene prose cleanup are explained
by artifact semantics and should remain.

The consistency question is therefore **mostly yes, with two material
exceptions**. Spell artifact ordering and all four citation extractors'
reference ordering assume numeric unit IDs instead of source-document order,
and spell/NPC checkpoint identities omit stable mapping policies. Both can
change durable results or reuse results produced under different semantics.
Smaller drift exists in common request preflight, scene semantic-validation
ownership, prompt cache-boundary coverage, and package surface conventions.

The shared-code question is **yes, but only for two narrow D&D-wide
responsibilities**: common chunk-extraction preflight and document-aware
source-reference ordering/canonicalization. They belong in
`internal/modules/dnd/shared`, not in the framework. Private response DTOs,
artifact mapping, structured LLM calls, prompt prose, response schemas,
metadata assembly, error prefixes, and typed test fakes should remain
package-owned; sharing them would require callbacks, type erasure, module
branching, or broad configuration.

Overall code quality is **good**. Construction, registration, cloning,
diagnostics, schema loading, prompt composition, and validator composition are
clear and consistently tested. The repository passes all current validation.
The recommended work is targeted correction and consolidation, not a redesign
of the extractor family.

### Final Module Comparison Matrix

| Module | Common contract | Required specialization | Prompt/schema boundary | Evidence and ordering | Provenance and tests |
| --- | --- | --- | --- | --- | --- |
| Spells | `dnd/spells` -> `dnd/spell-list`; typed LLM extractor; strict private DTO/schema; append merge and typed normalize/validate ([spec](../../internal/modules/dnd/extract/spells/extractor.go#L207)) | Prepared spell catalog and optional NPC registry projection; catalog prompt input ([constructor](../../internal/modules/dnd/extract/spells/extractor.go#L73)) | Shared evidence/input messages plus local task, instructions, catalog, and transcript; semantic catalog validation remains deterministic ([manifest](../../internal/modules/dnd/extract/spells/assets/prompts/dnd.spells.yaml#L23)) | Attaches current transcript ID and preserves invalid candidates, but sorts artifacts/references by numeric unit ID rather than document position ([canonicalization](../../internal/modules/dnd/extract/spells/canonicalize.go#L10)) | Prompt/schema/catalog/NPC projection fingerprints, but no mapping-policy fingerprint; broad extractor tests, incomplete full prompt cache-order assertion ([fingerprints](../../internal/modules/dnd/extract/spells/extractor.go#L144)) |
| NPCs | `dnd/npcs` -> `dnd/npc-list`; same typed lifecycle ([spec](../../internal/modules/dnd/extract/npcs/extractor.go#L159)) | Deterministic NPC identity derivation; campaign references remain request context ([mapping](../../internal/modules/dnd/extract/npcs/canonicalize.go#L94)) | Shared evidence/input messages plus NPC-local task/instructions/transcript; private schema owns transport only ([manifest](../../internal/modules/dnd/extract/npcs/assets/prompts/dnd.npcs.yaml#L17)) | Artifact order resolves document positions; reference list still sorts numeric IDs before exact deduplication ([canonicalization](../../internal/modules/dnd/extract/npcs/canonicalize.go#L11)) | Prompt/schema/identity fingerprints, but no mapping-policy fingerprint; weakest focused preflight matrix and partial prompt ordering coverage ([fingerprints](../../internal/modules/dnd/extract/npcs/extractor.go#L91)) |
| Combat turns | `dnd/combat-turns` -> `dnd/combat-turn-list`; same typed lifecycle ([spec](../../internal/modules/dnd/extract/combatturns/extractor.go#L201)) | Optional prepared NPC registry; all combat kinds remain raw validator candidates ([constructor](../../internal/modules/dnd/extract/combatturns/extractor.go#L68)) | Shared evidence/NPC/input messages plus combat-local task/instructions/transcript ([manifest](../../internal/modules/dnd/extract/combatturns/assets/prompts/dnd.combat_turns.yaml#L20)) | Artifact order uses valid source positions; extractor, normalizer, and invariant validator duplicate differing reference-order mechanics ([extractor](../../internal/modules/dnd/extract/combatturns/canonicalize.go#L10), [normalizer](../../internal/modules/dnd/normalize/combatturns/normalizer.go#L228)) | Mapping policy is fingerprinted; complete request preconditions, mapping, registry, and provider tests, but incomplete full prompt cache-order assertion ([fingerprints](../../internal/modules/dnd/extract/combatturns/extractor.go#L126)) |
| NPC interactions | `dnd/npc-interactions` -> `dnd/npc-interaction-list`; same typed lifecycle ([spec](../../internal/modules/dnd/extract/npcinteractions/extractor.go#L203)) | Required NPC registry and names-only projection; exact identity remains in focused domain package ([constructor](../../internal/modules/dnd/extract/npcinteractions/extractor.go#L68)) | Shared evidence/NPC/input messages plus interaction-local task/instructions/transcript ([manifest](../../internal/modules/dnd/extract/npcinteractions/assets/prompts/dnd.npc_interactions.yaml#L20)) | Extractor references sort numeric IDs, while the interaction model already owns correct document-aware canonicalization at too-narrow a layer ([extractor](../../internal/modules/dnd/extract/npcinteractions/canonicalize.go#L10), [model helper](../../internal/modules/dnd/npcinteractions/canonical.go#L17)) | Mapping, identity, prompt, schema, and registry projection are fingerprinted; focused suite omits nil-receiver and full prompt cache-order cases ([fingerprints](../../internal/modules/dnd/extract/npcinteractions/extractor.go#L126)) |
| Scene descriptions | `dnd/scene-descriptions` -> `dnd/scene-description-list`; same typed lifecycle ([spec](../../internal/modules/dnd/extract/scenedescriptions/extractor.go#L174)) | One summary per chunk, whole-chunk evidence, and fingerprinted prose trimming; no catalog/NPC projection ([mapping](../../internal/modules/dnd/extract/scenedescriptions/extractor.go#L150)) | Local task/instructions plus shared input/transcript; schema currently duplicates semantic enum/non-empty policy owned by shape validation ([schema](../../internal/modules/dnd/extract/scenedescriptions/assets/schemas/dnd_scene_descriptions_llm.v1.json#L8), [validator](../../internal/modules/dnd/validate/scenedescriptions/shape/validator.go#L49)) | Whole materialized chunk becomes one source range; citation ordering is not applicable | Mapping policy is fingerprinted; strongest full prompt order/cache test, but preflight omits nil receiver/context cases ([fingerprints](../../internal/modules/dnd/extract/scenedescriptions/extractor.go#L98), [prompt test](../../internal/modules/dnd/extract/scenedescriptions/scriptorium_assets_test.go#L15)) |

All five reject unknown options, register through the production D&D registrar,
return independently owned results, and use package-local structured response
types. No inconsistent secret handling, raw prompt/schema diagnostic exposure,
hidden result aliasing, or unregistered audited extractor was found.

### Prioritized Findings

#### High

1. **Source references and spell artifacts can be durably ordered contrary to
   transcript order.**
   - **Category:** correctness and architecture.
   - **Affected modules:** spell, NPC, combat-turn, and NPC-interaction
     extractors; related spell/combat/NPC normalizers and combat invariants.
   - **Evidence:** spell selects the smallest positive numeric unit ID
     ([`earliestSourceUnit`](../../internal/modules/dnd/extract/spells/canonicalize.go#L62));
     all four citation extractors sort reference endpoints numerically
     ([spell](../../internal/modules/dnd/extract/spells/canonicalize.go#L30),
     [NPC](../../internal/modules/dnd/extract/npcs/canonicalize.go#L31),
     [combat](../../internal/modules/dnd/extract/combatturns/canonicalize.go#L30),
     [interaction](../../internal/modules/dnd/extract/npcinteractions/canonicalize.go#L30)).
     Valid source documents require unique positive IDs, not monotonically
     increasing IDs
     ([`ValidateDocument`](../../internal/core/source/validation.go#L8)).
     The interaction model demonstrates the correct document-aware comparison
     ([`SourceRefLess`](../../internal/modules/dnd/npcinteractions/canonical.go#L51)).
   - **Impact:** valid evidence can be reordered away from transcript order;
     spell casts with invalid or later evidence can precede earlier valid
     casts. This changes durable list order, evidence presentation, merge input,
     and checkpointed results.
   - **Target state and owner:** move a document-backed `SourceRefOrder` to
     `internal/modules/dnd/shared`, with `EarliestValid` and `Canonicalize`
     operations. Preserve invalid candidates, exact deduplication, stable ties,
     nil/empty distinction, cloning, and deterministic invalid fallback.
     Artifact comparison, DTO conversion, source-ID attachment, and repair
     accounting remain local.
   - **Why shared:** the rule is a D&D-wide evidence invariant already
     implemented by extract, normalize, and validate consumers; continued
     copies have already diverged. A shared position index also reduces repeated
     `UnitIndex` scans from approximately `O(A log A * R * U)` ordering work to
     `O(U + A*R + A log A)` for `A` artifacts, `R` references, and `U` units.
   - **Migration/validation:** add non-monotonic, invalid, duplicate, nil/empty,
     aliasing, stable-tie, and repair-count tests; migrate the interaction model
     and combat normalize/invariant pair before extractors; add/bump mapping
     policy fingerprints so old checkpoints miss intentionally.

2. **Spell and NPC checkpoint identities omit stable mapping policies.**
   - **Category:** correctness and data integrity.
   - **Affected modules:** spell and NPC extractors.
   - **Evidence:** both extractors perform deterministic ordering,
     canonicalization, source attachment, and mapping
     ([spell mapping](../../internal/modules/dnd/extract/spells/canonicalize.go#L10),
     [NPC mapping](../../internal/modules/dnd/extract/npcs/canonicalize.go#L11)),
     but their fingerprint providers name catalog/projection or identity
     policies without a mapping policy
     ([spell fingerprints](../../internal/modules/dnd/extract/spells/extractor.go#L144),
     [NPC fingerprints](../../internal/modules/dnd/extract/npcs/extractor.go#L91)).
     Prepared fingerprints are lane-scoped
     ([collector](../../internal/framework/pipeline/prepared_fingerprints.go#L23))
     and restore requires exact normalized equality
     ([comparison](../../internal/framework/checkpoint/loader.go#L301)).
   - **Impact:** a mapping-policy code change can reuse a checkpoint produced
     under older artifact/evidence semantics when prompt and schema bytes are
     unchanged.
   - **Target state and owner:** each extractor owns an explicit stable
     mapping/canonicalization policy fingerprint. Metadata assembly stays
     package-local.
   - **Why preferable:** a local named semantic fingerprint directly closes
     the reuse gap; a generic metadata builder would only hide module-specific
     omissions behind configuration.
   - **Migration/validation:** add provider and prepared-checkpoint restore
     tests. Adding a fingerprint safely invalidates existing identities by full
     list mismatch; no artifact payload migration is required.

#### Medium

3. **Common extraction preflight is copied across five production callers and
   has already drifted in test protection.**
   - **Category:** duplication and testing.
   - **Affected modules:** all five extractors.
   - **Evidence:** every `Extract` validates the same context/source/chunk/unit
     prerequisites before calling
     [`ChunkPromptMaterial`](../../internal/modules/dnd/shared/extraction_inputs.go#L12),
     but focused coverage ranges from a complete spell/combat matrix to only
     cancellation and source mismatch for NPCs
     ([spell tests](../../internal/modules/dnd/extract/spells/extractor_test.go#L235),
     [NPC tests](../../internal/modules/dnd/extract/npcs/extractor_test.go#L139)).
   - **Impact:** validation order, error behavior, or a newly required common
     precondition can diverge silently among modules.
   - **Target state and owner:** add
     `shared.PrepareChunkExtraction(ctx, req) (contracts.LLMInputMaterial,
     error)` for cancellation, non-nil source/chunk, non-empty units, and
     matching cloned material. Receiver/client checks, specialized references,
     provider calls, typed results, and contextual wrapping remain local.
   - **Why shared:** this extends the existing common material boundary with
     one coherent invariant and serves five real callers without callbacks or
     module configuration.
   - **Migration/validation:** shared table tests own common inputs; package
     tests retain nil receiver/dependency, specialized reference, wrapped
     error, and provider cases. Preserve current validation order and useful
     package context.

4. **Scene semantic validity has two production owners.**
   - **Category:** architecture.
   - **Affected module:** scene descriptions.
   - **Evidence:** the private response schema enforces the scene-kind enum and
     non-empty title/summary
     ([schema](../../internal/modules/dnd/extract/scenedescriptions/assets/schemas/dnd_scene_descriptions_llm.v1.json#L8));
     deterministic shape validation independently enforces the same policy
     ([validator](../../internal/modules/dnd/validate/scenedescriptions/shape/validator.go#L49)).
     The documented schema boundary assigns semantic enum/non-empty rules to
     deterministic validators
     ([LLM internals](../internal/llm.md#L169)).
   - **Impact:** the two policies can drift and produce provider-dependent
     rejection before typed validation, while non-LLM artifacts see only the
     validator.
   - **Target state and owner:** retain JSON type, required/nullability, and
     unknown-field constraints in the package-private schema; make the scene
     shape validator the sole semantic owner.
   - **Why harmonize without sharing:** only scene has this duplicated policy;
     moving it to the existing validator removes an owner without inventing an
     abstraction.
   - **Migration/validation:** update schema structural tests and validator
     semantic tests, then expect the schema digest/checkpoint identity to
     change. Verify provider-decoded invalid candidates reach deterministic
     validation.

#### Low

5. **Four prompt suites do not fully protect the documented message-order and
   cache-boundary contract.**
   - **Category:** testing.
   - **Affected modules:** spells, NPCs, combat turns, and NPC interactions.
   - **Evidence:** scene descriptions asserts the complete prepared role order
     and ephemeral/no-cache placement
     ([test](../../internal/modules/dnd/extract/scenedescriptions/scriptorium_assets_test.go#L15));
     the four citation suites cover registration and selected inputs but not
     the full documented sequence
     ([spell tests](../../internal/modules/dnd/extract/spells/scriptorium_assets_test.go),
     [NPC tests](../../internal/modules/dnd/extract/npcs/scriptorium_assets_test.go),
     [combat tests](../../internal/modules/dnd/extract/combatturns/scriptorium_assets_test.go),
     [interaction tests](../../internal/modules/dnd/extract/npcinteractions/scriptorium_assets_test.go)).
   - **Impact:** manifest edits can move variable content into a cacheable
     prefix or reorder stable grounding without a focused failure, increasing
     request cost or reducing prompt quality.
   - **Target state and owner:** each package test should assert its complete
     documented prepared sequence and cache flags using the real registry.
   - **Why local:** lane inputs differ and the behavior belongs to each prompt
     manifest; shared test setup would obscure the boundary.
   - **Migration/validation:** assert roles/input identities/cache flags, not
     exact prompt text, byte counts, or hashes.

6. **Small exported-surface and defensive-behavior drift remains.**
   - **Category:** convention drift.
   - **Affected modules:** spells, combat turns, and D&D shared.
   - **Evidence:** spell and combat export unused singular `ArtifactType`
     constants while production uses typed `ArtifactKind`
     ([spell](../../internal/modules/dnd/extract/spells/extractor.go#L17),
     [combat](../../internal/modules/dnd/extract/combatturns/extractor.go#L17));
     spell `ManifestMetadata` lacks the nil guard used by the other four
     ([spell](../../internal/modules/dnd/extract/spells/extractor.go#L122),
     [NPC example](../../internal/modules/dnd/extract/npcs/extractor.go#L74));
     [`SourceRefCandidate`](../../internal/modules/dnd/shared/unit_refs.go#L90)
     has only a test caller, ignores its document parameter, and is unsafe for
     extractor provenance because it trusts model-supplied source identity.
   - **Impact:** the package surface presents competing artifact vocabulary,
     zero-value behavior is inconsistent, and an artificial shared API invites
     incorrect reuse. Immediate runtime impact is limited.
   - **Target state and owner:** delete the unused constants; align spell nil
     metadata behavior locally; delete `SourceRefCandidate` when the correct
     shared reference API lands.
   - **Why preferable:** deletion and local harmonization clarify existing
     contracts without adding a helper.
   - **Migration/validation:** graph search found no production consumers;
     compile all internal packages and add one spell zero-value metadata test.

#### Optional improvement

The current module documentation lists only four production consumers of
`ChunkPromptMaterial`, omitting scene descriptions
([documentation](../internal/modules.md#L67)). Correct that list when the shared
preflight boundary is documented. This is localized documentation maintenance,
not a separate production design finding.

No actionable issue was found in option strictness, production registration,
typed codec selection, result cloning, prompt/schema content redaction, local
prompt semantic ownership, catalog/NPC source-evidence separation, provider
error wrapping, or secret handling.

### Intentional Differences To Preserve

- **Prepared specialized state:** spells retains a catalog and optional NPC
  resolver; combat retains an optional NPC resolver; interactions requires one;
  NPC and scene extraction need only request material. Construction-time
  identity belongs only where the artifact uses it.
- **Reference slots:** catalog and NPC registry slots follow grounding needs.
  The interaction registry is required; combat/spell registry use is optional.
  Campaign references remain prompt context and never become evidence.
- **Evidence model:** scene descriptions cites the whole materialized chunk;
  forcing it through citation DTO/canonicalization machinery would weaken its
  one-summary-per-chunk contract.
- **Prompt assets:** only byte-identical canonical messages are shared. Local
  task, instruction, catalog, identity, and evidence wording changes with the
  artifact and must not be coupled.
- **Private schemas and DTOs:** similar `source_refs` fragments do not form a
  separately versioned wire contract. Package ownership keeps response changes
  aligned with mapping and diagnostics.
- **Prose handling:** scene title/summary trimming is a deliberate fingerprinted
  mapping policy; citation-lane names and enum candidates remain raw for their
  normalizers and validators.
- **Test organization:** file layout, typed fakes, schema compilation helpers,
  and real-registry prompt setup remain package-local. Equivalent risks need
  comparable coverage, not identical fixtures or filenames.

### Shared-Code Decisions

| Decision | Owner and scope | Why this is the narrow correct boundary |
| --- | --- | --- |
| Extract common preflight | `internal/modules/dnd/shared`; validate common typed extraction request state and return cloned matching `LLMInputMaterial` | Five current callers repeat one prerequisite to the existing `ChunkPromptMaterial` boundary. Receiver/dependency/specialized checks remain readable and local. |
| Extract source-reference order | `internal/modules/dnd/shared`; document-backed `SourceRefOrder.EarliestValid` and `.Canonicalize` over durable `[]source.SourceRef` | Multiple extract, normalize, model, and validate consumers must evolve together; the rule is D&D-wide but has no demonstrated non-D&D/framework consumer. |
| Harmonize mapping fingerprints | Spell and NPC extractor packages | The missing values are module-semantic; local named fingerprints are safer than a configurable metadata builder. |
| Harmonize scene validation ownership | Private scene schema plus `validate/scenedescriptions/shape` | Remove semantic keywords from the transport schema and keep the already registered durable validator as sole owner. No sharing is needed. |
| Harmonize prompt contract tests | Four citation extractor test suites | Each manifest owns its role/input/cache sequence; consistent assertions should stay beside distinct assets. |
| Harmonize preflight coverage | All five package suites after shared preflight | Shared tests own common branches; local tests retain package-visible context and specializations. |
| Harmonize package hygiene | Spell/combat extractors and D&D shared | Delete unused exports/artificial API and align spell metadata nil behavior without introducing a new abstraction. |

### Rejected Or Deferred Candidates

| Candidate | Decision and rationale |
| --- | --- |
| Deprecated `roster` slot asymmetry | **Deferred pending a product compatibility decision.** Configuration documents `roster` as a deprecated `party` alias ([config](../config.md#L526)), while scene removes it. Choose a removal release or uniform alias lifetime before changing slots and migration guidance. |
| Spell response-schema key/ID naming | **Deferred pending a provenance migration decision.** The spell names differ from the `_llm`/`.llm` convention, but schema identity is persisted metadata. Renaming needs an alias or an explicit manifest/checkpoint compatibility break. |
| Prompt registration/hash wrapper | **Rejected.** `shared.PromptAssetManifest` already owns coherent composition/hashing. Hiding filesystems, registries, `sync.Once`, and diagnostic nouns would require broad configuration. |
| Manifest/fingerprint builder | **Rejected.** Stable inputs are module-specific; a generic builder would accept the same keys/policies as arguments and could conceal omissions such as the current spell/NPC gap. |
| Generic artifact mapper | **Rejected.** Private DTO fields, identity, enums, and artifact types require callbacks, type erasure, or module branching. Only reference ordering is genuinely common. |
| Generic structured-LLM call wrapper | **Rejected.** Generic output and request configuration would hide an already clear framework client boundary without removing semantic work. |
| Shared error-prefix helper | **Rejected.** It would add a module-name parameter to replace three transparent lines and weaken local diagnostic ownership. |
| Shared response schemas or prompt prose | **Retain intentionally separate.** Similar structure/text is not an atomic shared contract; private schema and lane prompt changes should not propagate together. |
| Shared schema-test or provider-fake utilities | **Retain intentionally separate.** Typed DTOs and package assets are the behavior under test; central fixtures would couple suites and obscure failures. |
| Framework-level preflight/reference API | **Rejected.** No non-D&D consumer or framework-owned invariant was found. The D&D shared layer preserves dependency direction and domain ownership. |

### Recommended Refactoring Sequence

1. **Land checkpoint identity protection independently.** Add spell and NPC
   mapping-policy fingerprints with provider and checkpoint-restore tests.
   This is a small package-local change and protects all later semantic
   migrations from stale reuse.
2. **Consolidate source-reference mechanics.** Add and exhaustively test the
   D&D shared document-position index/API. Migrate the existing interaction
   model helper first, then combat normalize plus invariants, then NPC/spell
   normalizers, and finally the four citation extractors. Keep package mapping
   and repair accounting local; remove numeric comparators and the unused
   `SourceRefCandidate` only after all consumers move.
3. **Consolidate common extraction preflight.** Extend the existing shared
   chunk-material boundary, migrate one extractor to establish error/validation
   compatibility, then migrate the remaining four. Move common branch tables
   to shared tests and retain package-context smoke tests.
4. **Resolve scene validation ownership independently.** Adjust schema tests,
   remove semantic enum/non-empty constraints from the private schema, retain
   validator cases, and verify the expected schema fingerprint/checkpoint miss.
5. **Close prompt contract coverage.** Add full role/input/cache-boundary
   assertions to each citation prompt suite without shared fixtures or exact
   text/hash assertions.
6. **Apply low-risk package/documentation cleanup.** Remove unused
   `ArtifactType` constants, add the spell metadata nil guard/test, and update
   module documentation for the shared helper consumers and boundaries.

Each scope can be reviewed and reverted independently. The sequence is not a
decision-complete implementation plan; implementation should still pin exact
fingerprint values, exported names, error compatibility, and per-package test
cases.

### Validation And Residual Risks

Final validation on 2026-07-24:

```text
go test -count=1 ./...   PASS
go vet ./...             PASS
go build ./cmd/notarius  PASS
gofmt -l .               PASS (no files listed)
git diff --check         PASS
git diff --no-index --check /dev/null docs/roadmap/audit.md
                         PASS (no whitespace errors; exit 1 denotes differences)
```

The audit also checked that cited relative paths exist in the current working
tree. The audit changed no production code, tests, prompts, schemas, examples,
or current-behavior documentation.

Residual risks and limits:

- This was a static and deterministic-test audit; it did not evaluate live
  model extraction quality, prompt effectiveness, provider cache-hit rates, or
  token cost. Prompt changes still need representative human/model evaluation.
- Existing tests use mostly monotonic unit IDs, so the ordering defect is not a
  current failing test. The proposed non-monotonic fixtures are required before
  changing behavior.
- The exact durable order expected for invalid references must remain
  deterministic and diagnostics-friendly during API design; invalid references
  must not be discarded merely because default validators usually reject them
  later.
- Mapping and schema fingerprint additions intentionally invalidate prior
  checkpoint identities. Operators should be told to expect recomputation; no
  serialized artifact migration is otherwise indicated.
- The `roster` alias lifetime and spell schema-identity migration remain human
  product/compatibility decisions.
- Passing repository checks establishes current deterministic correctness, not
  absence of model-quality regressions or correctness under unrepresented
  source-document shapes.