refactor(#1646): route capability routers through Command Routing Hub per ADR-959 (#1647)

* refactor(#1646): route capability routers through Command Routing Hub per ADR-959

Phase 2 of parent #1641. Converts graphify, intel, and audit command
routers from hand-rolled if/else dispatch to routeHubCommandFamily,
implementing the ADR-959 §III(B) line 75 mandate. The three routers
now share the uniform dispatch shape with the 14 host routers.

src/cjs-command-router-adapter.cts
  * Imported ERROR_REASON from io.cjs.
  * UnknownCommand translation now passes ERROR_REASON.SDK_UNKNOWN_COMMAND
    as the second arg to error() — additive for host routers (their
    existing one-arg error callbacks ignore the second arg), required
    for capability routers whose tests assert reason === 'sdk_unknown_command'
    on the JSON-error envelope.

src/graphify-command-router.cts
  * Replaced 4-branch if/else with routeHubCommandFamily + handlers map.
  * Validation handlers (missing term, missing/invalid --budget) now
    return makeInvalidArgs(arg, reason, ERROR_REASON.USAGE) Results
    instead of calling error() directly (Q2=C, Q4=ii from grilling).
  * Success handlers keep direct output() calls.
  * Subcommands array is alphabetical for byte-identical 'Available:'
    text in the unknown-subcommand message.
  * The unknown-subcommand path is now owned by the Hub's manifest
    check (the adapter passes SDK_UNKNOWN_COMMAND).

src/intel-command-router.cts
  * Replaced 9-branch if/else with routeHubCommandFamily + handlers map.
  * Validation handlers (missing term, missing filePath for patch-meta
    and extract-exports) return makeInvalidArgs Results.
  * Preserved the timeAgo mutation in the non-raw status handler.
  * Preserved the lazy require('./intel.cjs') inside the route function.

src/audit-command-router.cts
  * routeAuditUat: routes through the Hub with a synthetic 'run'
    defaultSubcommand (no real subcommands). Gives uniform observability.
  * routeAuditOpen: captures --json in a closure, strips it from args
    before Hub dispatch (so it isn't mistaken for a subcommand by the
    manifest check), then branches on wantJson inside the handler to
    preserve the formatAuditReport success-path quirk.

docs/CONFIGURATION.md
  * Observability section: noted capability commands (graphify, intel,
    audit-uat, audit-open) now emit DispatchEvent records since #1646.

.changeset/capability-routers-via-hub.md
  * Changed fragment describing the user-visible audit-trail expansion.
    pr:0 placeholder will be backfilled after gh pr create returns the
    real PR number (DEFECT.CHANGESET-PR-FIELD-DRIFT).

Verification
  * graphify cutover tests: 119/119 pass (all unit, dispatch, behavior,
    error path, JSON-errors, and registry assertions)
  * intel cutover tests: 39/39 pass
  * audit cutover tests: 24/24 pass
  * bug-974-graphify-budget-missing-value regression test: pass
  * npm run test:unit (full suite): 2384 tests, 0 fail
  * gsd-test-summary on docker: outcome=passed, 0 failures
    (RULESET.PR-FLOW.docker-before-push)

JSON-error envelope parity verified byte-identical: reason values
('usage', 'sdk_unknown_command') and message texts are preserved
across all three routers' error paths.

* chore(#1646): backfill changeset pr: 1647 (DEFECT.CHANGESET-PR-FIELD-DRIFT)

src/cjs-command-router-adapter.cts

@@ -13,6 +13,12 @@
 // eslint-disable-next-line @typescript-eslint/no-require-imports
 import commandRoutingHub = require('./command-routing-hub.cjs');
 const { createHub, ERROR_KINDS } = commandRoutingHub;
+// Phase 2 (#1646): import ERROR_REASON so the UnknownCommand translation can
+// pass `sdk_unknown_command` as the second arg to error(), preserving the
+// JSON-error envelope contract that capability routers' tests assert on.
+// eslint-disable-next-line @typescript-eslint/no-require-imports
+import io = require('./io.cjs');
+const { ERROR_REASON } = io;
 
 // ─── Types ────────────────────────────────────────────────────────────────────
 
@@ -140,7 +146,12 @@ function routeHubCommandFamily({
 
   if (result.ok) return;
   if (result.kind === ERROR_KINDS.UnknownCommand) {
-    error(unknownMessage(subcommand ?? '', available));
+    // Phase 2 (#1646): pass SDK_UNKNOWN_COMMAND as the second arg so the
+    // JSON-error envelope (GSD_JSON_ERRORS=1) preserves the typed reason
+    // for downstream consumers. Additive for host routers (their existing
+    // one-arg `error` callbacks ignore the second arg); required for
+    // capability routers whose tests assert on `reason === 'sdk_unknown_command'`.
+    error(unknownMessage(subcommand ?? '', available), ERROR_REASON.SDK_UNKNOWN_COMMAND);
     return;
   }
   if (result.kind === ERROR_KINDS.InvalidArgs) {