feat(#972): graphify command cutover — first capability owning a command family (ADR-857 phase 4d-impl-2) (#975)

Migrate graphify into a Capability that owns its `graphify` command family,
dispatched via the registry (#961 mechanism) instead of a hardcoded case.
graphify is now an enable/disable plug-in.

- src/graphify-command-router.cts: routeGraphifyCommand (standard route*Command),
  reproduces the removed case EXACTLY (query +--budget, status, diff, build,
  hidden build snapshot, usage/unknown errors); injectable _graphify test seam.
- capabilities/graphify/capability.json: role feature, tier:full, skills:[graphify],
  config:{graphify.enabled default false}, commands:[{family:graphify, module,
  router:routeGraphifyCommand}].
- removed case 'graphify' from gsd-tools.cjs; graphify now flows
  default -> dispatchCapabilityCommand -> commandFamilies.graphify -> router.
- regenerated registry (commandFamilies/bySkill/configSchema/profileMembership/
  capabilityClusters for graphify); tier:full keeps 4c install/surface a no-op.

Equivalence-proven: 8 recording-mock unit tests assert the exact fn+args per
subcommand (budget, snapshot-vs-build); 9 subprocess tests assert distinguishing
output shapes; existing graphify tests pass unchanged through the new path.

Surfaced (not silently accepted): the pre-existing --budget-no-value NaN no-op
quirk, preserved for equivalence, filed separately.

Closes #972

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

src/graphify-command-router.cts

@@ -0,0 +1,89 @@
+'use strict';
+/**
+ * Graphify command router — CLI subcommand dispatcher for `gsd-tools graphify`.
+ *
+ * ADR-959 (phase 4d-impl-2) pilot: first real capability command cutover.
+ * Extracted from the hardcoded `case 'graphify':` arm in gsd-tools.cjs.
+ * Behaviour is preserved byte-for-behaviour from the prior inline case;
+ * the dispatch path now flows: default → dispatchCapabilityCommand →
+ * require(graphify-command-router.cjs) → routeGraphifyCommand.
+ *
+ * Router signature: { args, cwd, raw, error } — identical to the 12 existing
+ * host routers. No new handler/arg convention; the capability registry
+ * discovers this router by name.
+ *
+ * Arg indexing (preserved exactly from the original case):
+ *   args[0] = 'graphify'  (family — matched by dispatchCapabilityCommand)
+ *   args[1] = subcommand  (query | status | diff | build)
+ *   args[2] = term (query) | 'snapshot' (build snapshot)
+ *   args.indexOf('--budget') + 1 = budget value
+ *
+ * Test seam: pass `_graphify` in the options object to inject a recording mock
+ * instead of the real graphify module. The `_`-prefix follows the repo's
+ * established seam convention (see other routers). Production callers omit it.
+ */
+
+// eslint-disable-next-line @typescript-eslint/no-require-imports
+import graphify = require('./graphify.cjs');
+// eslint-disable-next-line @typescript-eslint/no-require-imports
+import core = require('./core.cjs');
+// eslint-disable-next-line @typescript-eslint/no-require-imports
+import io = require('./io.cjs');
+
+const { ERROR_REASON } = io;
+
+// ─── Types ────────────────────────────────────────────────────────────────────
+
+interface GraphifyModule {
+  graphifyQuery(cwd: string, term: string, opts: { budget: number | null }): unknown;
+  graphifyStatus(cwd: string): unknown;
+  graphifyDiff(cwd: string): unknown;
+  graphifyBuild(cwd: string): unknown;
+  writeSnapshot(cwd: string): unknown;
+}
+
+interface RouteGraphifyCommandOptions {
+  args: string[];
+  cwd: string;
+  raw: boolean;
+  error: (message: string, reason?: string) => void;
+  /** Test seam: inject a mock graphify module. Defaults to the real module. */
+  _graphify?: GraphifyModule;
+}
+
+// ─── Implementation ───────────────────────────────────────────────────────────
+
+function routeGraphifyCommand({ args, cwd, raw, error, _graphify }: RouteGraphifyCommandOptions): void {
+  const subcommand = args[1];
+  const g: GraphifyModule = _graphify ?? graphify;
+
+  if (subcommand === 'query') {
+    const term = args[2];
+    if (!term) {
+      error('Usage: gsd-tools graphify query <term>', ERROR_REASON.USAGE);
+      return;
+    }
+    const budgetIdx = args.indexOf('--budget');
+    const budget = budgetIdx !== -1 ? parseInt(args[budgetIdx + 1], 10) : null;
+    core.output(g.graphifyQuery(cwd, term, { budget }), raw);
+  } else if (subcommand === 'status') {
+    core.output(g.graphifyStatus(cwd), raw);
+  } else if (subcommand === 'diff') {
+    core.output(g.graphifyDiff(cwd), raw);
+  } else if (subcommand === 'build') {
+    if (args[2] === 'snapshot') {
+      core.output(g.writeSnapshot(cwd), raw);
+    } else {
+      core.output(g.graphifyBuild(cwd), raw);
+    }
+  } else {
+    error(
+      'Unknown graphify subcommand. Available: build, query, status, diff',
+      ERROR_REASON.SDK_UNKNOWN_COMMAND,
+    );
+  }
+}
+
+export = {
+  routeGraphifyCommand,
+};