feat(mcp): validate every documented API response at the apiFetch boundary

The stdio CLI read every API response as `payload: any` and picked fields out by
optional-chaining guesswork, so a renamed Worker field degraded silently at runtime.

gen-contract-api-schemas.ts generates @loopover/contract/api-schemas from
src/openapi/schemas.ts, which stays canonical and untouched: moving the schemas was
tried first and rejected because zod-to-openapi's .openapi() exists only on schemas
constructed after extendZodWithOpenApi runs, and both post-hoc naming routes (.openapi()
clones; .meta({id}) propagates through .nullable()/.extend() differently) changed the
published document. Generation with the names stripped keeps the document byte-identical
by construction, with --check in test:ci like the other generators.

The generator also emits CLI_RESPONSE_SCHEMAS, path -> response schema, derived from a
scan of the CLI's own literal api* call sites joined against the published document --
nothing hand-listed. The scanner requires the closing delimiter: the first draft
collected a template path's truncated prefix, which for a documented base path would
have validated the wrong endpoint's schema. apiGet/apiPost are overloaded so a literal
documented path returns the schema's inferred type, and apiFetch safeParses every
documented response under #9519's recorded posture: report and pass the payload through
untouched by default (returning zod's parse would strip fields the document
under-describes), throw under LOOPOVER_VALIDATE_RESPONSES for CI and self-host. The
warning dedupes per path so a polling loop cannot flood stderr, and lives in a hoisted
accessor because the entrypoint awaits runCli before module consts this far down
initialize.

Typing the responses immediately surfaced real drift: /v1/local/branch-analysis returns
predictedGate and dataQuality, which the document omitted entirely while two predict-gate
tools read them; both are now declared (as unknown until #9531 types the verdict). The
skipped-pr-audit call site moves its query out of the path template so the scanner keeps
it validated.

`payload: any` is extinct in the package and pinned by a grep gate test, along with the
table matching the scan exactly and the unvalidated remainder as a shrink-only list. The
posture tests drive the real compiled bin against a local server in both modes.

Author: JSONbored

package.json

@@ -25,6 +25,8 @@
     "loadtest:worker": "node --experimental-strip-types scripts/load-test-worker.ts",
     "mcp:tool-reference": "tsx scripts/gen-mcp-tool-reference.ts",
     "mcp:tool-reference:check": "tsx scripts/gen-mcp-tool-reference.ts --check",
+    "contract:api-schemas": "tsx scripts/gen-contract-api-schemas.ts",
+    "contract:api-schemas:check": "tsx scripts/gen-contract-api-schemas.ts --check",
     "command-reference": "node --experimental-strip-types scripts/gen-command-reference.ts",
     "command-reference:check": "node --experimental-strip-types scripts/gen-command-reference.ts --check",
     "selfhost:validate-observability": "node --experimental-strip-types scripts/validate-observability-configs.ts",
@@ -124,7 +126,7 @@
     "test:smoke:browser:install": "playwright install chromium",
     "test:smoke:browser": "node --experimental-strip-types scripts/smoke-ui-browser.ts",
     "pretest:ci": "npm run check-node-version",
-    "test:ci": "git diff --check && npm run actionlint && npm run lint:composite-actions && npm run db:migrations:check && npm run db:schema-drift:check && npm run selfhost:env-reference:check && npm run miner:env-reference:check && npm run selfhost:validate-observability && npm run cf-typegen:check && npm run build --workspace @loopover/engine && npm run build --workspace @loopover/discovery-index && npm run build:mcp && npm run build:miner && npm run build --workspace @loopover/ui-kit && npm run typecheck && npm run test:coverage && npm run test:engine-parity && npm run test:live-gate-parity && npm run test:driver-parity && npm run validate:mcp && npm run test --workspace @loopover/engine && npm run test:workers && npm run test:mcp-pack && npm run test:miner-pack && npm run test:engine-pack && npm run test:ui-kit-pack && npm run test:miner-deployment-docs-audit && npm run rees:test && npm run ui:openapi:check && npm run ui:version-audit && npm run docs:drift-check && npm run coverage-boltons:check && npm run import-specifiers:check && npm run ui-derived-types:check && npm run dead-source-files:check && npm run regate-sort-key:check && npm run command-redelivery-guards:check && npm run dispatch-gate-reasons:check && npm run validate:no-hand-written-js && npm run replay-runner-manifest:check && npm run coco-dev-versions:check && npm run branding-drift:check && npm run manifest:drift-check && npm run engine-parity:drift-check && npm run engines-nvmrc:check && npm run release-manifest:sync:check && npm run command-reference:check && npm run mcp:tool-reference:check && npm run ui:lint && npm run ui:typecheck && npm run ui:test && npm run ui:build",
+    "test:ci": "git diff --check && npm run actionlint && npm run lint:composite-actions && npm run db:migrations:check && npm run db:schema-drift:check && npm run selfhost:env-reference:check && npm run miner:env-reference:check && npm run selfhost:validate-observability && npm run cf-typegen:check && npm run build --workspace @loopover/engine && npm run build --workspace @loopover/discovery-index && npm run build:mcp && npm run build:miner && npm run build --workspace @loopover/ui-kit && npm run typecheck && npm run test:coverage && npm run test:engine-parity && npm run test:live-gate-parity && npm run test:driver-parity && npm run validate:mcp && npm run test --workspace @loopover/engine && npm run test:workers && npm run test:mcp-pack && npm run test:miner-pack && npm run test:engine-pack && npm run test:ui-kit-pack && npm run test:miner-deployment-docs-audit && npm run rees:test && npm run ui:openapi:check && npm run ui:version-audit && npm run docs:drift-check && npm run coverage-boltons:check && npm run import-specifiers:check && npm run ui-derived-types:check && npm run dead-source-files:check && npm run regate-sort-key:check && npm run command-redelivery-guards:check && npm run dispatch-gate-reasons:check && npm run validate:no-hand-written-js && npm run replay-runner-manifest:check && npm run coco-dev-versions:check && npm run branding-drift:check && npm run manifest:drift-check && npm run engine-parity:drift-check && npm run engines-nvmrc:check && npm run release-manifest:sync:check && npm run command-reference:check && npm run mcp:tool-reference:check && npm run contract:api-schemas:check && npm run ui:lint && npm run ui:typecheck && npm run ui:test && npm run ui:build",
     "test:release": "npm run test:ci && npm run changelog:check",
     "test:release:mcp": "npm run test:ci",
     "test:watch": "vitest",

packages/loopover-contract/package.json

@@ -55,6 +55,10 @@
     "./public-api": {
       "types": "./dist/public-api.d.ts",
       "default": "./dist/public-api.js"
+    },
+    "./api-schemas": {
+      "types": "./dist/api-schemas.d.ts",
+      "default": "./dist/api-schemas.js"
     }
   },
   "files": [