Repoint correlation_id → trace_id across the app's browser + server consumers, and regenerate src/gen

1 — Re-sync the contract mirror + regenerate src/gen

Per openapi/AGENTS.md + HR-22, the contract source of truth is pramaan-functions. The vendored mirror was synced from functions origin/main (Story-1453, PR #378) and codegen run with the repo's own command — no hand-edits to src/gen.

cp ../pramaan-functions/openapi/app-api.json openapi/app-api.json
pnpm codegen   # rm -rf src/gen/{types,zod,schemas,client,hooks,index.ts} && kubb generate

The contract delta is small but ripples wide: the ErrorResponse schema's @description literally embeds the phrase “a nested error object plus a top-level trace_id”, and that description is copied into every endpoint's error-response schema. So the regen touches 152 generated files (813 ins / 813 del) — all deterministic description + field renames, codegen-drift clean.

2 — Drop the cid mint at the edge (proxy.ts)

The proxy no longer mints or stamps x-pramaan-correlation-id on the request or the response. Request identity now flows on trace_id alone, and the proxy observability log keys on trace_id/span_id (the correlation_id / had_incoming_id fields are simply omitted now). The x-pramaan-route header and the entire pramaan-docs ADR-104 traceparent path are untouched.

// src/proxy.ts — stampRequestContext (cid mint removed; traceparent kept)
request.headers.set(REQUEST_ROUTE_HEADER, request.nextUrl.pathname);
const traceparent = resolveTraceparent(request.headers.get(TRACEPARENT_HEADER));
// ...mint/respect/strip traceparent exactly as before...
return { traceId, spanId };   // no correlationId, no hadIncomingId

Critically, the Bug-1471 fix in src/lib/outbound-headers.ts is byte-for-byte untouched — the connected X-Ray graph depends on outbound backend calls carrying the active @vercel/otel span's traceparent, and that single-sourcing is preserved.

3 — Repoint the six named consumers to trace_id

Each consumer now reads/carries trace_id instead of correlation_id. The browser source of truth is the RSC layout's <meta name="x-pramaan-trace-id"> (surfaced in Story-1447); the server source is the proxy-stamped traceparent header.

So a bug report or a client render error now carries the live X-Ray trace_id end to end — support resolves the failing request directly in the X-Ray graph.

4 — Regen-forced server builders (the “server” half)

Because ErrorResponse is built with satisfies ErrorResponse in the BFF, the regen forces every error-body builder to switch correlation_id → trace_id: the shared _helpers.ts (apiError/validationError) and the 16 route handlers that hand-roll their own inline builders. They all route through one shared resolver:

// src/app/api/internal/_helpers.ts
export function resolveRequestTraceId(request: NextRequest): string {
  // On this BFF surface the @vercel/otel route span CONTINUES the proxy-stamped
  // inbound traceparent (Bug-1471), so its exported X-Ray trace id EQUALS the
  // traceparent's trace id. Reading the header gives the same value without
  // importing the OTel API into every /api/internal route's module graph.
  return parseTraceparent(request.headers.get(TRACEPARENT_HEADER) ?? "")?.traceId ?? "";
}

5 — Delete the dead cid files (accept-the-fold)

Per the founder decision to align with the admin repoint (Story-1455), this PR deletes the now-dead correlation-id files rather than leaving them inert — absorbing the app file-deletion originally scoped to Story-1457 (APP-RIP). The only remaining RIP is the functions cross-lane contract cleanup (Story-1456).

• Deleted correlation-banner.tsx (+ story + test) and correlation-provider.tsx (BrowserCorrelationProvider / useBrowserCorrelationId) — unused after the repoint + mint-drop.
• Replaced correlation-reference.tsx with trace-reference.tsx: the user-facing “share this reference” component on the 7 error/not-found surfaces + the error toast now shows the request trace_id (read from the x-pramaan-trace-id meta via useSyncExternalStore — no hydration mismatch) instead of the retired correlation id. shouldShowCorrelationReference → shouldShowTraceReference.
• layout.tsx — dropped the provider wrapper, the banner, the dead x-pramaan-correlation-id meta tag, and the correlation imports/compute (keeps the trace_id meta).
• logger-browser.ts — removed the now-unused exposeBrowserCorrelationId seeder; the browser logger keys on trace_id from the meta tag.
• proxy-observability.ts — correlationId/hadIncomingId optional and omitted from the log when absent.
• Kept correlation.ts / correlation-context.ts — still used by REQUEST_ROUTE_HEADER in proxy.ts, the /api/health route, gateway.ts, and (deliberately untouched) the Bug-1471 outbound-headers.ts correlation context.

Verification green

• pnpm typecheck — clean.
• pnpm lint — clean (1 pre-existing no-img-element warning in avatar.tsx, unrelated).
• pnpm test — 555 passed across 95 files (consumer/proxy/diagnostics/bug-report tests repointed to trace_id). One file, tests/unit/matters-internal-route.test.ts, hits a pre-existing parallel-load @/gen-barrel import timeout under the full suite (proven identical on baseline HEAD); it passes reliably in isolation.
• pnpm build — pass.
• git diff --check — clean.
• Codegen-drift — src/gen regenerated from the synced mirror with the repo's pnpm codegen; no hand-edits.
• Bug-1471 — src/lib/outbound-headers.ts untouched (the connected-graph traceparent join is preserved).

Out of scope (dependent / sibling EPIC-1400 tickets)

This PR absorbed Story-1457's app file-deletion (accept-the-fold), so the correlation-provider/-banner/-reference files are gone. What remains by design: correlation.ts / correlation-context.ts stay because still-live out-of-scope code depends on them — REQUEST_ROUTE_HEADER in proxy.ts, the /api/health route (keeps correlation_id per the unchanged HealthResponse), gateway.ts, and the Bug-1471 outbound-headers.ts correlation context (deliberately untouched). Story-1455 (R7c) is the parallel admin repoint; Story-1456 (R7d) is the functions cid rip-out. The live staging connected-graph test across X-Ray + CloudWatch + Logfire is the EPIC-1400 program-level acceptance gate.

Files changed

212 file(s), +1182 / -1260 lines