Remove legacy shared prompt package and update docs

docs/internal/overview.md

@@ -55,6 +55,7 @@ Production module packages live under `internal/modules`:
 
 - `input/seriatim`
 - `chunk/generic`
+- `chunk/dnd/scenes`
 - `extract/dnd/spells`
 - `merge/appendorder`
 - `normalize/noop`
@@ -63,6 +64,12 @@ Production module packages live under `internal/modules`:
 Each module package owns its contract implementation, module spec,
 registration, options, focused tests, and module-specific errors.
 
+Module-owned prompts and schemas live in each module's shallow `assets/prompts`
+and `assets/schemas` directories. Shared reusable D&D prompt fragments live in
+`internal/modules/sharedassets`.
+
+Shared asset package: `internal/modules/sharedassets`
+
 ## Fixtures And Tests
 
 The repository uses focused package tests plus a fixture-driven CLI workflow.
@@ -81,6 +88,7 @@ servers.
 
 - Source-format details stay in input modules and integration docs.
 - Extraction-domain details stay in extract modules and artifact docs.
+- Shared prompt fragments stay in `internal/modules/sharedassets`.
 - Provider wire details stay in the LLM runtime and provider integration docs.
 - Durable output contracts belong in integration docs.
 - Operator procedures belong in `docs/operations.md`, not internal docs.