fix(cache): fold generation params (reasoning.effort/max_tokens) into semantic cache signature

[Laksopan23]

What

Fixes #15149 — folds generation params into the semantic-cache signature so two temperature: 0 requests that differ only in reasoning.effort / max_tokens (or top_k, seed, stop, penalties, logit_bias) no longer collide on the same cache entry.

⚠️ base-red inherited: #15100

Root cause

generateSignature() hashed {model, messages, temperature, top_p} + the output contract (tools/tool_choice/response_format — #12307/#12734), and generateDirectHash() folded the same contract, but neither carried generation params: outputContractOf() never extracted them. A request with reasoning: {"effort": "none"} was therefore stored and looked up under the exact signature a later reasoning: {"effort": "max"} request computes — the second request got x-omniroute-cache: HIT with the first request's body.

Fix

outputContractOf() (src/lib/semanticCache.ts) now also extracts, when present:

reasoning, reasoning_effort, max_tokens, max_completion_tokens, top_k, seed, stop, presence_penalty, frequency_penalty, logit_bias

Every read/store call site already passes that contract through — legacy signature (read fallback, non-streaming store, streaming store) and the Layer-1 direct hash (manager lookup/store) — so no call-site changes were needed. Requests carrying none of these fields still get null from outputContractOf(), so plain-chat signatures — and every cache entry already written for them — stay byte-identical.

Also adjusts tests/unit/chat-combo-live-test.test.ts: it hand-seeded its cached entry with a bare legacy signature while the production read path folds the request's max_tokens; the seed now uses the same contract the production paths compute (the test previously only passed because outputContractOf returned null for generation params).

Tests (TDD)

• New tests/unit/15149-semantic-cache-signature-generation-params.test.ts — written first, red on base (all collision assertions fail: identical digests), 7/7 green with the fix:
  • effort none vs max → different signatures; effort vs absent → different
  • max_tokens 1500 vs 800 vs absent → different signatures
  • every generation param named in the issue splits the signature from plain chat
  • Layer-1 direct hash folds them too (manager lookup/store path)
  • plain chat keeps the byte-identical legacy signature (existing entries survive)
• Retention: 12 semantic-cache files 113/113, chat-combo-live-test 5/5, plus cache-signature-roundtrip, chatcore-*, chat-route-edge-cases, cache-config-route, db-logs-cache — all green.
• npm run test:vitest: 51/52 files pass; mcp-server/__tests__/audit.test.ts failed only under parallel run contention and passes 8/8 in isolation.
• Gates: ESLint (with suppressions, as CI runs) on changed files: 0 errors; tsc -p tsconfig.typecheck-core.json: clean; Prettier applied; pre-commit hooks (lint-staged, docs-sync, t11 any-budget, tracked-artifacts, ai-attribution) all passed.

Base-red failures (inherited, not this PR)

Local runs on pristine origin/release/v3.8.52 code reproduce exactly the same failures as this branch:

• tests/unit/provider-request-failure-pipeline.test.ts — 6 failures (pipelinePayloads null) — identical count on base code
• tests/unit/chatcore-translation-paths.test.ts — 3 failures (same family) — identical count on base code

Tracked by #15100.

[Laksopan23]

CI run 1 — evidence

Passing (8): Change Classification, Merge integrity (changelog + generated skills), API Route Typecheck, Vitest (fast-path), No new ESLint warnings, semgrep, semgrep-cloud-platform/scan, (Build skipped advisory).

Docs Gates (fast-path) — inherited base-red, not this PR:

✗ README.md — stale version: "OmniRoute v3.8.51" — package.json is 3.8.52
✗ llm.txt — stale version: "Current version:** 3.8.51" — package.json is 3.8.52
✗ 2 STRICT drift(s) detected.

Verified inheritance:

• git diff origin/release/v3.8.52 -- README.md llm.txt → empty (this PR touches neither file)
• base llm.txt:11 = **Current version:** 3.8.51 while base package.json version = 3.8.52 → the version bump landed without the doc sync on release/v3.8.52

Tracked by the base-red issue for this branch: #15100.

(Additional local base-red reproduced identically on pristine base code, for context: tests/unit/provider-request-failure-pipeline.test.ts 6 failures, tests/unit/chatcore-translation-paths.test.ts 3 failures — same counts with and without this branch.)

[Laksopan23]

CI run 1 — full failure attribution (all inherited base-red)

Final check results: 8 pass / 4 fail (plus Build skipped advisory).

Failing checks

1. Docs Gates (fast-path) — version drift on release/v3.8.52:

✗ README.md — stale version: "OmniRoute v3.8.51" — package.json is 3.8.52
✗ llm.txt — stale version: "Current version:** 3.8.51" — package.json is 3.8.52

• This PR touches neither file (git diff origin/release/v3.8.52 -- README.md llm.txt → empty)
• Documented hard failure of the base itself in the base-red issue: 🔴 Release branch not green: release/v3.8.52 #15100 ("Docs sync + fabricated-docs (strict): ✗ README.md — stale version…", from the chore(release): open v3.8.52 development cycle push)

2. Fast Quality Gates — mutation-test-coverage:

✗ 24 covering unit test(s) across 8 module(s) are missing from stryker.conf.json tap.testFiles

All 24 are pre-existing test files (antigravity-verify-account-403…, circuit-breaker-kind-cooldown-escalation-14960…, authz/peer-stamp…, …) over pre-existing stryker modules (routeGuard.ts, error.ts, circuitBreaker.ts, comboStructure.ts, …). Neither the new test file nor src/lib/semanticCache.ts appears — this PR adds nothing to that list. All other FQG sub-gates passed.

3. Unit Tests fast-path (1/4, 3/4, 4/4) — 9 failing tests, none cache-related:

Shard	Failing tests
1/4	glm-executor (expects pinned claude-cli/2.1.258, code ships 2.1.280), opencode-geo-block-rotation ×3 (451≠200…)
3/4	adobe-firefly-test-browser-guard, connection-test-respects-operator-disable
4/4	check-docs-counts-sync (fails with the same "2 STRICT drift(s)" as Docs Gates → #15100), combo-lockout-quota-reset-6863, issue-14629-commandcode-400-recovery-unreachable

Local base-vs-branch proof (same 9 failures both ways)

Ran the failing files locally in two passes:

1. with this branch's code → EXIT=1, 9 failures
2. after restoring pristine git show origin/release/v3.8.52:src/lib/semanticCache.ts → EXIT=1, identical 9 failures (same files, same positions)

adobe-firefly-test-browser-guard:1:304 / :1180
check-docs-counts-sync:1:2481
combo-lockout-quota-reset-6863:1:2766
glm-executor:1:3447
issue-14629-commandcode-400-recovery-unreachable:1:427
opencode-geo-block-rotation:1:7631 / :9339 / :10451

(connection-test-respects-operator-disable is CI-only and does not import the semantic cache.) Additionally provider-request-failure-pipeline (6) and chatcore-translation-paths (3) fail identically on pristine base code in the local full sweep.

Passing (8)

Change Classification · Merge integrity (changelog + generated skills) · API Route Typecheck · Vitest (fast-path) · No new ESLint warnings · semgrep · semgrep-cloud-platform/scan · Mergify Merge Protections (skip)

No failing check involves src/lib/semanticCache.ts or the cache test suites (new test, 12 semantic-cache files, chat-combo-live-test all green locally; not among CI failures).

[Laksopan23]

Retriggering CI: base has moved to \dbe703a000\ since the last run — the inherited reds (Docs Gates via #15113, unit fast-path failures incl. glm pin / geo rotation / 400-recovery / connection-test via the base-red drain rounds) reproduce green on the current base under the canonical harness. FQG mutation-gate drift stays tracked as base-red (#15185 / #15227).

[Laksopan23]

CI evidence after merging base tip 5282351753 (comment 3/3 — supersedes the FQG part of comment 2)

After f2ce517bac, GitHub's PR merge ref included base commits that landed after this branch's merge-base, so complexity-ratchets measured 27 files (3 mine + 24 base-side) and attributed open-sse/utils/opencodeHeaders.ts: 0 → 1 and open-sse/translator/deepseekWebTools.ts: 5 → 6 to this PR. Merging origin/release/v3.8.52 (63dcfe6183) removed the gap: git diff --name-only origin/release/v3.8.52 HEAD is exactly the 3 files of this PR, local check:complexity-ratchets --base-ref origin/release/v3.8.52 = 1 file in scope, 0 violations, and Fast Quality Gates now passes (complexity + mutation gate).

Remaining reds are all base-side / infra — none touch this PR's diff:

Check	Root cause	Proof
Docs Sync (Strict)	i18n drift: docs/architecture/QUALITY_GATES.md (source-changed)	node scripts/i18n/check-translation-drift.mjs FAILs in this worktree, whose docs/ is byte-identical to base tip (diff vs base = 3 code files only)
Lint	failing step is npm run audit:deps — 16 vulns incl. critical next GHSA-vcvr-r3jv-pc5j (fix needs next@16.3.8, outside the pinned range)	this PR changes no dependencies
Unit Tests (6/8)	tests/unit/usage-pending-sweep.test.ts → assert.ok(getPendingById().size > 5000)	file untouched by this PR; passes locally under the canonical harness (exit 0)
Vitest (MCP/UI)	431/431 files, 2841/2841 tests pass; 4 unhandled window is not defined from tests/unit/ui/flowCanvas.test.tsx	file untouched by this PR
Build	npm run build step cancelled (runner/timeout), no compile error	steps show cancelled Run npm run build
Gate / CI + Gate / Quality	downstream admission: fail citing fast-gates: required result is failure while required checks above are red	base's own runs at 52823517 are red too: CI #36950659779 (Gate / CI), Quality Gates #36950659850

⚠️ base-red inherited: #15246 (release/v3.8.52 not green) + the items above from the 52823517 push wave.