chore: drop upstream gsd issue and pr governance

MSD does not use an issue tracker, and the inherited GSD community gates
auto-closed PR #1 for lacking an issue-numbered title. Remove them:

- workflows: require-issue-link, pr-title-validator,
  auto-close-unsolicited-prs, pr-template-format, close-draft-prs(-sweep),
  auto-label-issues, auto-branch, duplicate-check, duplicate-sweep,
  remove-duplicate-label
- GSD PR and issue templates, plus the scripts only they used
  (require-issue-link-policy, pr-template-policy, pr-changed-files) and
  their tests
- workflow lists in ci-test-scope, ci-pr-mergeability,
  workflow-maintainer-skip, lint-pr-check-project-dir, the docs-guard
  baseline and the conformance tiers
- CONTRIBUTING: PR-against-next flow with no issue or template; PR titles
  are conventional without an issue ref; ADR/PRD files use the PR number
- CONTEXT.md: drop the PR-template predicates (k328, templates-mandatory)

docs/CONTEXT-INDEX.json

@@ -1,6 +1,6 @@
 {
   "schemaVersion": 1,
-  "count": 285,
+  "count": 280,
   "classes": {
     "ARCH": 1,
     "CI": 2,
@@ -13,12 +13,12 @@
     "PHASE": 8,
     "PLANNING": 3,
     "PR": 2,
-    "PRED": 68,
+    "PRED": 64,
     "PROBE": 12,
     "PROC": 14,
     "PROHIB": 10,
     "RELEASE-NOTES": 31,
-    "RULESET": 60,
+    "RULESET": 59,
     "SEAM": 14,
     "SESSION": 9,
     "WAVE": 5,
@@ -496,26 +496,6 @@
       "klass": "PRED",
       "value": "cr-ack-vs-real-review"
     },
-    {
-      "id": "PRED.k328.audit-list",
-      "klass": "PRED",
-      "value": "[heading-matches-class, closing-keyword-present, changeset-fragment-or-no-changelog-label]"
-    },
-    {
-      "id": "PRED.k328.canonical-source",
-      "klass": "PRED",
-      "value": "CONTRIBUTING.md L48,L64,L81 (template links) + .github/PULL_REQUEST_TEMPLATE/{fix,enhancement,feature}.md L1 (heading text)"
-    },
-    {
-      "id": "PRED.k328.k100-restatement",
-      "klass": "PRED",
-      "value": "heading must match issue class: bug→## Fix PR, enhancement→## Enhancement PR, feature→## Feature PR"
-    },
-    {
-      "id": "PRED.k328.signal",
-      "klass": "PRED",
-      "value": "pr-template-typed-heading-required"
-    },
     {
       "id": "PRED.k329.body",
       "klass": "PRED",
@@ -1061,11 +1041,6 @@
       "klass": "RULESET",
       "value": "before ANY git push of any fix to any PR, run msd-test (docker on the remote, mirrors ubuntu CI) and confirm exit 0. macOS-local node --test is NOT a substitute — many failures are platform-specific (path separators, case sensitivity, locale, fs semantics). Watchdog with Monitor on the output log; never set a sleep/timer and walk away. Source: user feedback 2026-05-16 — \"we don't set a timer we actively watch and record results in real time as possible\". SUPERSEDED 2026-07-17: 'confirm exit 0' is a false-green trap — piping/backgrounding can report exit 0 on a failed suite; gate on the verdict-line outcome:\"passed\" for the exact HEAD sha instead. See CLAUDE.md's msd-test rule and the msd-test-is-ref-based-commit-first predicate for the current, correct gating contract."
     },
-    {
-      "id": "RULESET.PR-FLOW.templates-mandatory",
-      "klass": "RULESET",
-      "value": "every gh pr create|edit|gh issue create|edit MUST first invoke the gh-templates-first skill and Read (Read tool, not Bash cat — k321 read-tracking) the matching template in .github/. Apply ALL required sections; never write freeform bodies. Repo enforces this via msd-pr-template-policy GitHub Action which flags any non-templated body — the bot allows the PR to stay open only because authors are contributors-or-higher, but the warning is a real complaint that must be cured. Source: user feedback 2026-05-16 (multi-message escalation) — \"the whole reason i have that github action is because you fucking blow through and ignore using the templates\""
-    },
     {
       "id": "RULESET.PR-SCOPE.one-concern-per-pr",
       "klass": "RULESET",