diff --git a/docs/conventions.md b/docs/conventions.md
index 266bc2b..119dabf 100644
--- a/docs/conventions.md
+++ b/docs/conventions.md
@@ -29,14 +29,23 @@
   `community.general` is an approved, stable dependency and its modules may be
   selected freely when appropriate; declare and pin the collection wherever a
   role or collection depends on it.
-- Trust the documented contract of each Ansible module, including its
-  idempotence and change detection.
-- Gather state only when the result controls necessary behavior that the
-  responsible module cannot determine. Fingerprints, checksums, sidecar state,
-  manual drift detection, and speculative recovery paths require an explicit
-  acceptance criterion and rationale. Do not precede a declarative module with
-  a probe or recreate its internal logic unless a concrete requirement cannot
-  be expressed by the module itself.
+- Do not strengthen the specification. Implement the requested invariants
+  without inventing additional guarantees for integrity, provenance, drift
+  recovery, corruption detection, rollback, or similar behavior.
+- Prefer convergence over state inspection. Declare what should be true and
+  let the relevant module reconcile it.
+- Trust Ansible's abstraction boundary. A module that manages state owns the
+  checks necessary to manage that state. Inspect it beforehand only when the
+  observed state is independently required.
+- Complexity requires a requirement. Every additional task, conditional,
+  registered variable, or state probe must correspond to behavior the role is
+  required to provide.
+- Persisted role-private state is a design smell. Fingerprints, checksum
+  databases, stamps, manifests, and similar bookkeeping require specific
+  justification.
+- **Assume convergence first.** Before adding machinery for an edge case,
+  determine whether rerunning the ordinary desired-state operations already
+  repairs it.
 - Consider whether a conditional task or a notified handler best expresses the
   dependency. A `when` condition keeps triggers visible at the action site but
   grows with their number. Notifications keep the action independent of the
diff --git a/docs/roadmap/implementation.md b/docs/roadmap/implementation.md
index e3a3225..b661d22 100644
--- a/docs/roadmap/implementation.md
+++ b/docs/roadmap/implementation.md
@@ -1,12 +1,311 @@
-# Active Implementation Plan
+# Implementation Plan 0001: Simplify Seriatim Source Installation
 
-There is no approved implementation plan at present.
+Status: proposed
 
-Feature 0001 has been reopened with a revised, minimal specification at
-`docs/roadmap/features/0001-seriatim-source-installation.md`. Prepare its
-numbered staged implementation plan here only after that revised roadmap and
-the workspace implementation conventions have been reviewed.
+Target executor: GPT-5.6-Terra
 
-The prior Audita plan was withdrawn because it propagated the superseded
-Seriatim build-state and hardening architecture. Git history preserves that
-research, but those execution instructions must not be used.
+Feature roadmap:
+[Feature 0001: Seriatim Source Installation](features/0001-seriatim-source-installation.md)
+
+## Objective
+
+Replace the current overengineered `ansible-role-seriatim` implementation with
+the concise, module-driven role defined by Feature 0001. Preserve the useful
+role metadata and supported installation outcome while removing persistent
+build state, duplicated module logic, speculative recovery, and obsolete test
+coverage.
+
+## Execution Rules
+
+- Execute Stage 1 and Stage 2 in numeric order.
+- Before each stage, confirm its preconditions and the working-tree state of
+  the owning repository.
+- Modify only `ansible-role-seriatim`. Treat this workspace plan,
+  `rakestraw-ansible`, and `../seriatim` as read-only during implementation.
+- Preserve unrelated and pre-existing changes. Stop if the role repository is
+  not clean at a stage boundary unless its changes are the expected output of
+  the immediately preceding stage.
+- Follow `docs/conventions.md` and the Feature 0001 task flow. Trust the
+  idempotence and change detection of `apt`, Snap, `file`, and `git`.
+- Keep the three rebuild triggers directly on the build task. Do not create an
+  intermediate rebuild fact, build handlers, or a handler flush.
+- Do not reintroduce fingerprints, checksums, sidecar build state, manual Git
+  cleanup, staged replacement, compiler inspection, or malformed-path
+  recovery.
+- Use fully qualified collection names and `argv` for command execution.
+- Run each stage's validation before committing it. Do not begin Stage 2 if
+  Stage 1 fails validation.
+- Commit each completed stage with the plain-English message specified below.
+  Do not push.
+- Treat `/usr/local/src/seriatim` and `/usr/local/bin/seriatim` as disposable
+  role-managed state during local integration. Do not remove the obsolete
+  `/usr/local/src/seriatim.ansible-build-state` directory from the host; the
+  revised role simply stops managing it.
+
+## Starting State and Preconditions
+
+- `ansible-role-seriatim` is clean on `main` at commit `6fb1aa2` and is ten
+  commits ahead of its current `origin/main`.
+- The workspace plan and revised feature roadmap are reviewed and committed
+  before out-of-band execution begins.
+- The local controller and managed host are Ubuntu 26.04 `amd64`, with
+  passwordless privilege escalation available for the approved integration
+  test.
+- Workspace tooling is available in `../.venv/bin` from the role repository:
+  Ansible Core 2.21.3 and ansible-lint 26.8.0.
+- `community.general` 13.3.0 remains pinned in
+  `collections/requirements.yml`, and the Go Snap channel `1.26/stable` is
+  available.
+- Upstream tag `v1.5.0` resolves to commit
+  `0fc92f364316c874d366b00cdc884a33e1900b25`.
+- The upstream `v1.5.0` contract remains:
+  - Go module requirement 1.25;
+  - build package `./cmd/seriatim`;
+  - `CGO_ENABLED=0`, `GOWORK=off`, `GOTOOLCHAIN=local`, and `-trimpath`;
+  - linker flags `-s -w -X
+    gitea.maximumdirect.net/eric/seriatim/internal/buildinfo.Version=<version>`;
+  - `seriatim --version` output `seriatim version <version>`.
+- Upstream tag `v1.4.0` resolves to
+  `9202ccddb962ab499f0772d3c01efdf2ff703077` and supports the same build and
+  version contracts for the selected-version integration case.
+
+## Repository Scope
+
+- `ansible-role-seriatim` owns every implementation, interface, README, and
+  repository-local test change in this plan.
+- `ansible-workspace-dnd` owns the roadmap, this plan, and aggregate status but
+  remains unchanged during out-of-band implementation.
+- `../seriatim` is the authoritative read-only application contract.
+- `rakestraw-ansible` is a read-only style reference.
+- Every other repository in `workspace.yml` remains unchanged.
+
+## Fixed Public Interface
+
+Retain exactly these public defaults:
+
+| Variable | Default | Purpose |
+| --- | --- | --- |
+| `seriatim_version` | `v1.5.0` | Git revision and version injected into the executable |
+| `seriatim_repository_url` | `https://gitea.maximumdirect.net/eric/seriatim.git` | Source repository |
+| `seriatim_source_dir` | `/usr/local/src/seriatim` | Managed source checkout |
+| `seriatim_binary_path` | `/usr/local/bin/seriatim` | Installed executable |
+| `seriatim_manage_build_dependencies` | `true` | Whether to install Git and Go |
+| `seriatim_go_snap_channel` | `1.26/stable` | Go Snap channel |
+
+The Go executable, package, build flags, linker symbol, and build environment
+are fixed implementation details. The selected version is both the Git ref and
+the value injected into the binary.
+
+## Stage 1: Replace the Role with the Minimal Implementation
+
+### Objective
+
+Replace the existing role contract, task graph, documentation, and baseline
+test harness with one coherent minimal implementation that installs and
+validates the default Seriatim release idempotently.
+
+### Preconditions
+
+- The starting-state commits and upstream contracts above are unchanged.
+- `ansible-role-seriatim` has no uncommitted changes.
+- The default managed paths contain no data that must be preserved.
+
+### Owning Repository
+
+`ansible-role-seriatim`
+
+### Required Changes
+
+1. Reduce `defaults/main.yml` and `meta/argument_specs.yml` to the six variables
+   in the Fixed Public Interface. Retain useful role and Galaxy metadata in
+   `meta/main.yml`.
+2. Replace the imported task structure with one readable `tasks/main.yml` and
+   remove the obsolete task files. Implement approximately this task flow:
+   1. assert Ubuntu 26.04 and architecture `x86_64` or `aarch64`;
+   2. install Git with `ansible.builtin.apt` when dependency management is
+      enabled;
+   3. install the classic Go Snap from `seriatim_go_snap_channel` with
+      `community.general.snap` when dependency management is enabled;
+   4. create the source and binary parent directories as `root:root` mode
+      `0755` with one `ansible.builtin.file` loop;
+   5. check out `seriatim_version` with `ansible.builtin.git`, using
+      `seriatim_repository_url`, `seriatim_source_dir`, and `force: true`, and
+      register the module result;
+   6. inspect `seriatim_binary_path` with `ansible.builtin.stat`;
+   7. run `seriatim_binary_path --version` only when the binary exists,
+      registering the result without reporting change or failing the play;
+   8. build directly to `seriatim_binary_path` when the Git task changed, the
+      binary is absent, or the version command failed or returned anything
+      other than `seriatim version {{ seriatim_version }}`;
+   9. converge recursive `root:root` source ownership and binary
+      `root:root` mode `0755` with one item-driven `ansible.builtin.file` loop;
+   10. validate the binary version after a build without reporting change.
+3. Put the rebuild expression directly on the build command. Register the
+   build result for post-build validation and mark the command changed only
+   when it runs.
+4. Invoke `/snap/bin/go build` with `argv`, the fixed package, flags, linker
+   value, output path, working directory, and environment from the upstream
+   contract. Do not turn those fixed values into defaults or facts.
+5. Remove all code for Git executable discovery, Go executable and compiler
+   validation, manual Git status/reset/clean, resolved-commit facts, temporary
+   build directories, build inputs, fingerprints, checksums, sidecar state,
+   special path-object recovery, and transactional installation.
+6. Do not add `handlers/main.yml`; the build, permission, and validation tasks
+   execute in normal order.
+7. Rewrite the README to document the six-variable interface, privilege and
+   fact requirements, dependency opt-out behavior, authoritative Git checkout,
+   direct build contract, three rebuild triggers, installed metadata, and
+   validation commands. Remove every claim or example tied to deleted
+   variables, state files, staging, compiler invalidation, or failure
+   preservation.
+8. Rewrite `tests/verify.yml` to check only the selected commit, recursive
+   source ownership, binary type and metadata, and exact version output.
+9. Replace `tests/integration` with a focused baseline driver that installs the
+   pinned collection locally, runs syntax checking and ansible-lint, converges
+   the default role, runs `tests/verify.yml`, and requires `changed=0` and
+   `failed=0` on an immediate repeat. Keep `tests/converge.yml`,
+   `tests/inventory`, and the compatible platform-guard playbook concise.
+
+### Validation
+
+From `ansible-role-seriatim`, run:
+
+```sh
+tests/integration
+! rg -n \
+  'seriatim_(source_ref|build_version|build_state_dir|go_binary|go_build_flags|go_ldflags|go_package)|fingerprint|checksum' \
+  defaults meta tasks tests README.md
+git diff --check
+git status --short
+```
+
+Expected result: static validation passes; the default source resolves to
+`0fc92f364316c874d366b00cdc884a33e1900b25`; the binary reports
+`seriatim version v1.5.0` with `root:root` ownership and mode `0755`; the
+immediate repeat reports `changed=0` and `failed=0`; and only intended Stage 1
+changes remain before commit.
+
+### Completion Criteria
+
+- The public interface contains exactly six defaults and matching argument
+  specifications.
+- The role's effective task flow matches the roadmap without intermediate
+  rebuild state or handlers.
+- No role code or active documentation references the obsolete sidecar state
+  or removed variables.
+- The baseline integration driver passes and proves default idempotence.
+- No repository outside `ansible-role-seriatim` changed.
+
+### Commit
+
+Commit message: `Simplify the Seriatim role`
+
+## Stage 2: Add Focused Behavioral Coverage
+
+### Objective
+
+Extend the baseline test harness only far enough to prove the revised feature's
+selected rebuild triggers, metadata convergence, platform guard, and final
+default state.
+
+### Preconditions
+
+- Stage 1 is committed and the role repository is otherwise clean.
+- The Stage 1 baseline integration test passes.
+- Upstream tags `v1.4.0` and `v1.5.0` remain available.
+
+### Owning Repository
+
+`ansible-role-seriatim`
+
+### Required Changes
+
+1. Extend `tests/integration` using strict shell options, repository-relative
+   paths, a private temporary directory, and cleanup that restores the default
+   `v1.5.0` installation when possible.
+2. Retain the baseline convergence, verification, and clean-repeat cases, then
+   add focused cases for:
+   - an absent binary causing one rebuild followed by an unchanged run;
+   - an executable that reports the wrong version causing one rebuild followed
+     by an unchanged run;
+   - binary ownership or mode drift being repaired by the ordinary `file` task
+     without requiring a rebuild, as shown by the captured Ansible task output;
+   - selecting `v1.4.0`, confirming its commit and version output, and reaching
+     an unchanged repeat;
+   - restoring `v1.5.0`, confirming its commit and version output, and reaching
+     a final unchanged repeat;
+   - unsupported distribution, Ubuntu release, and architecture inputs failing
+     before creating application state at isolated temporary paths.
+3. Keep recap checks simple and fail the driver on hidden task failures or
+   unexpected changes during idempotence runs.
+4. Keep test mutation limited to the two declared managed paths and paths below
+   the driver's private temporary directory.
+5. Do not add cases for fingerprints, checksums, compiler changes, source-tree
+   dirt, staged failure preservation, custom-parent recovery, symbolic links,
+   malformed state, or the obsolete build-state directory.
+6. Update the README test section to describe the actual focused suite and its
+   managed-host effects without advertising superseded behavior.
+
+### Validation
+
+From `ansible-role-seriatim`, run:
+
+```sh
+tests/integration
+git diff --check
+git status --short
+```
+
+Then confirm the restored default installation:
+
+```sh
+/usr/local/bin/seriatim --version
+sudo git -C /usr/local/src/seriatim rev-parse HEAD
+sudo stat -c '%U:%G %a' /usr/local/bin/seriatim
+```
+
+Expected result: the complete focused suite passes; all expected negative
+platform cases are recognized; the final repeat reports `changed=0` and
+`failed=0`; the restored executable reports `seriatim version v1.5.0`; the
+source is at `0fc92f364316c874d366b00cdc884a33e1900b25`; binary metadata is
+`root:root 755`; and only intended Stage 2 changes remain before commit.
+
+### Completion Criteria
+
+- Every Feature 0001 acceptance criterion has direct test or static evidence.
+- The suite tests only the revised operational contract and contains no
+  superseded hardening matrix.
+- The README, defaults, argument specifications, task flow, and tests agree.
+- The default local installation is restored and idempotent.
+- No repository outside `ansible-role-seriatim` changed.
+
+### Commit
+
+Commit message: `Focus Seriatim integration coverage`
+
+## Final Validation and Handoff
+
+After Stage 2, run:
+
+```sh
+tests/integration
+git log --oneline -2
+git status --short --branch
+cd ..
+./scripts/status
+```
+
+The implementation handoff must report:
+
+- the Stage 1 and Stage 2 commit hashes in order;
+- the final integration result and clean-repeat recap;
+- the final source commit, version output, ownership, and mode;
+- any deviation from this plan or the feature roadmap;
+- any remaining implementation concern or potential future hardening item.
+
+Do not edit workspace roadmap or status files, mark Feature 0001 `done`, or
+push during out-of-band execution. Completion requires subsequent review.
+
+## Progress Notes
+
+No stages have been executed.
diff --git a/docs/status.md b/docs/status.md
index f051539..529414e 100644
--- a/docs/status.md
+++ b/docs/status.md
@@ -1,11 +1,11 @@
 # Workspace Status
 
-Last updated: 2026-09-07
+Last updated: 2026-09-08
 
 Current milestone: MVP standalone application roles
 
-Current focus: Review the revised Feature 0001 specification and prepare a
-minimal Seriatim simplification plan.
+Current focus: Review the staged implementation plan for the Feature 0001
+Seriatim simplification.
 
 | ID | Deliverable | Owner | State | Evidence or next step |
 | --- | --- | --- | --- | --- |
@@ -18,7 +18,7 @@ minimal Seriatim simplification plan.
 | M1-02 | Standalone application roles | role repositories | in_progress | Simplify Seriatim before continuing to other roles |
 | M1-03 | Suite-level pipeline role | ansible-role-dnd-pipeline | proposed | Begin after standalone role interfaces stabilize |
 | M1-04 | Collection assembly | ansible-collection-dnd | proposed | Select and implement the pipeline-role incorporation mechanism |
-| F0001 | Install Seriatim from pinned source | ansible-role-seriatim | ready | Revised roadmap ready; staged simplification plan is next |
+| F0001 | Install Seriatim from pinned source | ansible-role-seriatim | ready | Review `docs/roadmap/implementation.md` |
 | F0002 | Install and configure Audita | ansible-role-audita | proposed | Replan after the simplified Seriatim role is reviewed |
 
 ## Updating This File