fix(5): decision-coverage gate parses <action> XML tag bodies for D-NN citations (#155)

* test(5): add failing test for decision IDs inside <objective>/<tasks>/<task>/<action> XML bodies

Regression test for issue #5 — the translation gate (check.decision-coverage-plan)
is blind to D-NN citations placed inside XML tag bodies by gsd-planner.

Maintainer acceptance criteria (verbatim, issue #5):
  "Gate parses <action> tag bodies for decision ID citations; regression test
   with XML-tag plan body covers all decision IDs."

Five new test cases added to the 'XML tag body citation parsing (issue #5)' suite:
  1. RED: five decisions cited only in <objective>/<action> bodies → gate fails (before fix)
  2. Non-canonical tag <comment> → must NOT count (negative control, passes)
  3. Plain prose under undesignated heading → must NOT count (negative control, passes)
  4. Self-closing <action/> → no crash, D-NN not covered (passes)
  5. D-NN in <objective> body → should count (also fails before fix, GREEN after)

Tests 1 and 5 are the load-bearing RED cases. All others are negative controls.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(5): extend extractPlanSections to scan <objective>/<tasks>/<task>/<action> for D-NN citations

Closes #5.

Root cause: extractPlanSections() in check-decision-coverage.ts collected only
front-matter (must_haves/truths/objective) and body lines under designated
markdown headings. The gsd-planner spec (agents/gsd-planner.md line 66) says
'Task actions reference the decision ID they implement (e.g., "per D-03")' and
emits citations inside <action> tag bodies — a location the gate could not see.

Fix: add extractXmlTagBodies() helper that matches the four canonical planner
XML tags (<objective>, <tasks>, <task>, <action>) via a deliberately narrow
regex (no XML parser library — D2 design decision). The helper output is
appended to the designated string inside extractPlanSections(), making any
D-NN citation inside those tag bodies count toward coverage.

Maintainer acceptance criteria (verbatim, issue #5):
  "Gate parses <action> tag bodies for decision ID citations; regression test
   with XML-tag plan body covers all decision IDs."

Self-closing tags (<action/>) are safely ignored — the capturing group does
not match. Non-canonical tags (<comment>, <note>, etc.) are not in the
alternation and are ignored by design.

The CJS surface for check-decision-coverage.ts does NOT have a generator
(gen-decisions.mjs covers decisions.ts, not this gate). No CJS artifact
exists for this module. Per the generator framework established in PR #154
(ADR-3524), a CJS migration is a follow-up; this PR focuses on the TS fix.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* docs(5): clarify in gsd-planner.md that decision-coverage gate reads XML tag bodies

Adds a parenthetical note to the existing self-check bullet (line 66) explaining
which locations the gate scans so the planner's own guidance and the gate's
behavior are explicitly aligned.

Refs #5. No behavior change — documentation truthing only.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* chore(5): add changeset fragment for decision-coverage XML body fix

Refs #5.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* docs(5): extract Interface Context for Executors into reference file to pass planner-decomposition gate

gsd-planner.md was 49446 chars after the XML-tag clarification added in
this PR, exceeding the 48K threshold enforced by
tests/planner-decomposition.test.cjs. Extracted the "Interface Context
for Executors" section (~2137 chars) into
get-shit-done/references/planner-interface-context.md, leaving a one-line
pointer in gsd-planner.md. New normalized size: 47310 chars (1842 chars
under threshold).

Refs #5

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix(5): register planner-interface-context.md in INVENTORY.md and manifest

- Bump References headline from 61 to 62 to match filesystem count
- Add planner-interface-context.md row in Modular Planner Decomposition table
- Update footnote from 61 to 62 top-level references
- Regenerate docs/INVENTORY-MANIFEST.json via gen-inventory-manifest.cjs --write

Fixes inventory-counts and inventory-manifest-sync CI failures caused by the
extraction commit (32e8950f) adding a new reference file without updating the
inventory artefacts.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

docs/INVENTORY-MANIFEST.json

@@ -226,6 +226,7 @@
       "planner-gap-closure.md",
       "planner-graphify-auto-update.md",
       "planner-human-verify-mode.md",
+      "planner-interface-context.md",
       "planner-mvp-mode.md",
       "planner-reviews.md",
       "planner-revision.md",

docs/INVENTORY.md

@@ -262,7 +262,7 @@ Full roster at `get-shit-done/workflows/*.md`. Workflows are thin orchestrators
 
 ---
 
-## References (61 shipped)
+## References (62 shipped)
 
 Full roster at `get-shit-done/references/*.md`. References are shared knowledge documents that workflows and agents `@-reference`. The groupings below match [`docs/ARCHITECTURE.md`](ARCHITECTURE.md#references-get-shit-donereferencesmd) — core, workflow, thinking-model clusters, and the modular planner decomposition.
 
@@ -353,11 +353,12 @@ The `gsd-planner` agent is decomposed into a core agent plus reference modules t
 | `planner-mvp-mode.md` | Vertical-slice planning rules for MVP mode. |
 | `planner-human-verify-mode.md` | Rules for `workflow.human_verify_mode = end-of-phase`: suppress `checkpoint:human-verify` task emission and route deferred items via `<verify><human-check>`. |
 | `planner-graphify-auto-update.md` | How `load_graph_context` surfaces `.last-build-status.json` auto-update state (running / failed / stale head) alongside the existing staleness annotation. Opt-in via `graphify.auto_update` (#3347). |
+| `planner-interface-context.md` | Interface context rules for executors — how to extract key interfaces/types/exports from existing code and document new interfaces that downstream plans will consume. |
 | `skeleton-template.md` | SKELETON.md template emitted for new-project Walking Skeleton (Phase 1 + `--mvp`). |
 | `user-story-template.md` | User story format for MVP planning — "As a / I want to / So that" structured fields. |
 | `spidr-splitting.md` | SPIDR splitting decomposition rules for handling large user stories in MVP mode. |
 
-> **Subdirectory:** `get-shit-done/references/few-shot-examples/` contains additional few-shot examples (`plan-checker.md`, `verifier.md`) that are referenced from specific agents. These are not counted in the 61 top-level references.
+> **Subdirectory:** `get-shit-done/references/few-shot-examples/` contains additional few-shot examples (`plan-checker.md`, `verifier.md`) that are referenced from specific agents. These are not counted in the 62 top-level references.
 
 ---