fix(#1196): wire discuss loop step for capability hooks (#1199)

* fix(#1196): wire discuss loop step for capability hooks

discuss was contract-declared (gsd:loop-host marker, in POINT_ORDER and
LOOP_HOST_CONTRACT) but structurally unwireable: discuss-phase.md had no
`loop render-hooks` dispatch and was absent from the conformance gate's
HOST_LOOP_FILES, so capabilities could never wire discuss:pre/discuss:post.

- discuss-phase.md: add minimal discuss:pre (before analyze_phase) and
  discuss:post (after write_context) render-hooks dispatch steps that
  delegate consumption to a new shared reference (kept under the 32KB
  #2551 budget; no inline subagent dispatch token).
- references/loop-hook-dispatch.md: new canonical, point-agnostic contract
  for consuming `loop render-hooks --raw` activeHooks (contribution/step/
  gate) — single source for hook consumption across host loops.
- gen-loop-host-contract.cjs: derive HOST_LOOP_FILES from STEP_WORKFLOWS and
  export scanWiredPoints()/getWiredLoopPoints() (throws on a missing host
  file) — one source of truth for the host-loop file + wired-point set.
- phase6-capstone-conformance.test.cjs: consume the derived HOST_LOOP_FILES
  and shared scanWiredPoints (was a hand-maintained duplicate omitting
  discuss-phase.md + a duplicated regex).
- gen-capability-registry.cjs: add validateHooksWired() gen-time guard that
  rejects a capability hook declared at a valid-but-unwired loop point, with
  a clear remediation message — failure now surfaces at gen --check/--write
  time instead of deep in the full conformance suite.
- tests (capability-registry.test.cjs): regression + anti-pattern parity
  guards (every loop-host marker is in STEP_WORKFLOWS/HOST_LOOP_FILES;
  POINT_ORDER === flattened LOOP_HOST_CONTRACT) so no step can drift into
  the discuss-class gap again.
- docs/INVENTORY*: register the new reference.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* chore(#1196): backfill changeset PR number (#1199)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

gsd-core/workflows/discuss-phase.md

@@ -293,6 +293,13 @@ Read `@~/.claude/gsd-core/references/scout-codebase.md` — it contains the phas
 3. Build internal `<codebase_context>` per the reference's output schema
 </step>
 
+<step name="dispatch_discuss_pre_hooks">
+```bash
+DISCUSS_PRE_HOOKS_JSON=$(gsd_run loop render-hooks discuss:pre --raw)
+```
+Apply each entry in `activeHooks` per @~/.claude/gsd-core/references/loop-hook-dispatch.md. Empty list → continue to `analyze_phase`.
+</step>
+
 <step name="analyze_phase">
 Analyze the phase to identify gray areas. Use both `prior_decisions` and `codebase_context` to ground the analysis.
 
@@ -405,6 +412,13 @@ The template documents variable substitutions and conditional sections. Substitu
 Write the file.
 </step>
 
+<step name="dispatch_discuss_post_hooks">
+```bash
+DISCUSS_POST_HOOKS_JSON=$(gsd_run loop render-hooks discuss:post --raw)
+```
+Apply each entry in `activeHooks` per @~/.claude/gsd-core/references/loop-hook-dispatch.md. Empty list → continue to `confirm_creation`.
+</step>
+
 <step name="confirm_creation">
 Present summary and next steps: