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>

scripts/gen-capability-registry.cjs

@@ -34,6 +34,9 @@ const SCHEMA_VERSION = '1';
 // registry generator and the loop-host-contract generator share one source of truth.
 const { LOOP_HOST_CONTRACT } = require('../gsd-core/bin/lib/loop-host-contract.cjs');
 
+// Wired-points helper — tells us which points actually have render-hooks call sites.
+const { getWiredLoopPoints } = require('./gen-loop-host-contract.cjs');
+
 // Canonical point order — explicit constant (do NOT rely on Set insertion order).
 // Used for point-ordering semantics in consumes-satisfiability validation and topo-sort.
 const POINT_ORDER = [
@@ -1961,6 +1964,54 @@ function runConfigFormatParityGate(capMap) {
   }
 }
 
+// ─── Gen-time wired guard ─────────────────────────────────────────────────────
+
+/**
+ * Validate that every hook point declared by a capability has a corresponding
+ * `loop render-hooks <point>` call site in one of the host-loop workflow files.
+ *
+ * Only valid loop points (in VALID_LOOP_POINTS) are checked here. Invalid points
+ * are already caught by validateStep/validateContribution/validateGate — do not
+ * double-report.
+ *
+ * @param {object}   cap       Validated capability object.
+ * @param {Set<string>} wiredSet  Set of points that have call sites in host workflows.
+ * @returns {string[]}          Array of error strings; empty means all points are wired.
+ */
+function validateHooksWired(cap, wiredSet) {
+  const errors = [];
+  const capId = cap.id || '(unknown)';
+
+  function checkPoint(point, groupName, idx) {
+    // Only flag valid points that are unwired — invalid points are schema-validator's job.
+    if (!VALID_LOOP_POINTS.has(point)) return;
+    if (!wiredSet.has(point)) {
+      errors.push(
+        'capability "' + capId + '" ' + groupName + '[' + idx + '].point "' + point +
+        '" is declared but not wired in any host-loop workflow ' +
+        '(no `loop render-hooks ' + point + '` call site). ' +
+        'Wire the call site in the host workflow ' +
+        '(see scripts/gen-loop-host-contract.cjs STEP_WORKFLOWS) or remove the hook.',
+      );
+    }
+  }
+
+  for (let i = 0; i < (cap.steps || []).length; i++) {
+    const hook = cap.steps[i];
+    if (hook.point !== undefined) checkPoint(hook.point, 'steps', i);
+  }
+  for (let i = 0; i < (cap.contributions || []).length; i++) {
+    const hook = cap.contributions[i];
+    if (hook.point !== undefined) checkPoint(hook.point, 'contributions', i);
+  }
+  for (let i = 0; i < (cap.gates || []).length; i++) {
+    const hook = cap.gates[i];
+    if (hook.point !== undefined) checkPoint(hook.point, 'gates', i);
+  }
+
+  return errors;
+}
+
 // ─── Registry builder ─────────────────────────────────────────────────────────
 
 /**
@@ -1982,6 +2033,10 @@ function loadAndValidate(centralKeys, capabilitiesDir) {
     return { capMap, errors };
   }
 
+  // Compute wired points ONCE before iterating capabilities so the filesystem
+  // scan is not repeated per-capability. ROOT is the repo root (defined at top of file).
+  const wiredSet = getWiredLoopPoints(ROOT);
+
   const folderEntries = fs.readdirSync(resolvedCapDir, { withFileTypes: true })
     .filter((e) => e.isDirectory())
     .map((e) => e.name)
@@ -2013,6 +2068,13 @@ function loadAndValidate(centralKeys, capabilitiesDir) {
       continue;
     }
 
+    // Gen-time wired guard: reject hooks that declare a valid point with no call site.
+    const wiredErrors = validateHooksWired(cap, wiredSet);
+    if (wiredErrors.length > 0) {
+      for (const e of wiredErrors) errors.push(folderId + '/capability.json: ' + e);
+      continue;
+    }
+
     const fragmentErrors = materializeHookFragments(cap, path.dirname(capPath));
     if (fragmentErrors.length > 0) {
       for (const e of fragmentErrors) errors.push(folderId + '/capability.json: ' + e);
@@ -2499,6 +2561,7 @@ module.exports = {
   POINT_TO_CONTRACT,
   HOST_ARTIFACT_EARLIEST_POINT_IDX,
   SCHEMA_VERSION,
+  validateHooksWired,
   // ADR-857 phase 4a: derived views + gates
   deriveCapabilityClusters,
   deriveProfileMembership,