docs: repair links left dangling by the operations-doc removal

Untracking the ops docs broke every reference to them. Repoints or removes
those references across README, architecture, ROADMAP, the archive index,
lifecycle TESTING, the hardening plan, and the security docs — pointing at
the issue tracker where a live task list was meant, and dropping the entry
entirely where it only existed to link an internal file.

Also fixes two pre-existing broken links found by validating every relative
link in the tracked docs:
- README linked docs/OPEN_SOURCE_READINESS.md, which never existed
  (underscores vs hyphens).
- reticulum-daemon/README.md linked a local Claude session plan at
  ../../.claude/plans/enchanted-strolling-rocket.md — outside the repo, and
  a path that would have shipped publicly pointing at nothing.

All relative links in tracked markdown now resolve: 0 broken.
audit-secrets.sh still 5/5.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/lifecycle/TESTING.md

@@ -57,7 +57,7 @@ rollout for fedimint-gateway/-clientd, icon/naming fixes) is **done and
 shipped**: the generated-secrets system is a platform primitive
 (`container.generated_secrets`, see `docs/app-manifest-spec.md`), the
 manifests declare it, and the single-node gate went green on .228 on
-2026-06-23. Day-to-day open items live in `docs/UNIFIED-TASK-TRACKER.md` —
+2026-06-23. Day-to-day open items live in the issue tracker —
 don't add session logs here.
 
 ---
@@ -235,7 +235,7 @@ We don't have a performance harness yet. Add as L6 lands:
 
 ## Release gates
 
-1.8.0 ships only when ALL of (see `docs/UNIFIED-TASK-TRACKER.md` for the live
+1.8.0 ships only when ALL of (see the issue tracker for the live
 priority-ordered list of what's still open across these):
 
 1. ☑ Bitcoin-stops fix verified live on a fresh node (`tests/lifecycle/bats/bitcoin-knots.bats`