Release v3.8.42 (#5459)

Release v3.8.42 — full CHANGELOG in CHANGELOG.md.

CI: 103 checks green incl. CodeQL (all languages), Semgrep, all 8 unit shards,
coverage, Node 24 compat, and integration tests. Full unit suite validated
locally: 19437 pass / 0 fail. The 3 red checks are advisory and do not gate
main (no required status checks): SonarCloud/SonarQube new-code coverage gate,
and PR Test Policy (test-masking detector flagging the legitimate dead-Phind
provider removal in #5530 — reviewed, correct).

Includes cycle-close reconciliation + repair of inherited base-red tests from
#5480/#5527/#5427/#5521 that the PR->release fast-path did not exercise.

CLAUDE.md

@@ -35,7 +35,7 @@ For full test matrix, see `CONTRIBUTING.md` → "Running Tests". For deep archit
 
 ## Project at a Glance
 
-**OmniRoute** — unified AI proxy/router. One endpoint, 237 LLM providers, auto-fallback.
+**OmniRoute** — unified AI proxy/router. One endpoint, 236 LLM providers, auto-fallback.
 
 | Layer         | Location                | Purpose                                                                                                                                                |
 | ------------- | ----------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------ |
@@ -539,6 +539,7 @@ the stale-enforcement added in Fase 6A.3.
 18. Every bug fix must be validated before shipping: a failing-then-passing unit/integration test (TDD) OR a documented live test on the production VPS (192.168.0.15). A fix without either is not merged. See Testing → "Bug fix / issue triage protocol" for the full decision tree.
 19. Never develop on the shared main checkout. Every development task runs in its own git worktree on its own dedicated branch, and you MUST confirm the base branch with the operator (e.g. via `AskUserQuestion`) before creating the worktree/branch — never assume `main` or the currently checked-out branch. A `git checkout` in the shared checkout silently destroys other sessions' uncommitted work. Tear down only the worktrees/branches you created (by name, never `fix/*`/`feat/*` wildcards), leave other sessions' worktrees untouched, and end on the branch you started on (the active `release/vX.Y.Z`, never `main`). See Git Workflow → "Worktree isolation".
 20. PII redaction/sanitization is **opt-in — never on by default**. OmniRoute proxies for self-hosted/local LLMs where the operator owns the data, so mutating request/response payloads by default would silently corrupt legitimate traffic. The two data-mutating PII feature flags **MUST** keep `defaultValue: "false"` in `src/shared/constants/featureFlagDefinitions.ts`: `PII_REDACTION_ENABLED` (request-side) and `PII_RESPONSE_SANITIZATION` (response + streaming). All three application points — `src/lib/guardrails/piiMasker.ts` (request guardrail), `src/lib/piiSanitizer.ts` (response), `src/lib/streamingPiiTransform.ts` (SSE) — are gated on these flags; with both off the `pii-masker` guardrail still runs but never mutates payloads (data passes through untouched). Flipping either default to `"true"` requires explicit operator approval. The regression guard is `tests/unit/pii-opt-in-default.test.ts` (asserts both definition defaults + behavioral pass-through). Opt-in is per-operator via env or the settings/DB override (`src/lib/db/featureFlags.ts`), never a silent default. See `docs/security/GUARDRAILS.md`.
+21. **Release-freeze — the release branch is frozen to campaign merges while a `/generate-release` is running.** `/generate-release` opens a marker issue labeled `release-freeze` at the start of reconciliation (Phase 0a) and closes it once the release PR squash-merges to `main`. Before merging **any** PR into the active `release/vX.Y.Z` branch, every campaign workflow (`/review-issues`, `/review-prs`, `/implement-features`, `/green-prs`, `/port-upstream-*`) **MUST** check `gh issue list --repo diegosouzapw/OmniRoute --label release-freeze --state open` — if a freeze is active, **HOLD the merge** (leave the PR ready and open; do NOT merge to the release branch), tell the operator, and resume once the freeze lifts. This is a **coordination signal, not a permission lock**: the release captain and the campaign sessions share the `diegosouzapw` identity, so a GitHub branch-protection lock cannot distinguish them — only this honored marker prevents the mid-release commit races that forced full CHANGELOG re-reconciliation in v3.8.40/v3.8.41 (a parallel campaign advanced `release/vX.Y.Z` by 34 commits mid-run). The release captain's own reconciliation/cycle-open pushes are exempt — they *are* the release. Fixes that must land during a freeze (a homologation finding) follow the post-merge read-only rule: land on `main` first via `fix/release-vX.Y.Z-*`.
 
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