[b3nw]

Summary

Adds Time-to-First-Token (TTFT) metrics to call log telemetry and surfaces a sortable TTFT column in the RequestLogger dashboard.

• Adds migration 171_call_logs_ttft_ms.sql adding nullable ttft_ms INTEGER to call_logs.
• Records TTFT during SSE streaming responses in chatCore.ts and attemptLogging.ts. Failed or aborted streams safely record NULL to avoid poisoning statistical aggregations.
• Surfaces TTFT column in RequestLoggerV2.tsx with adaptive formatting (ms for <1000ms, s for >=1000ms) and full null-aware sorting (ttft_asc and ttft_desc).
• Adds changelog fragment changelog.d/features/ttft-column-requestlogger.md.

Related Issues

N/A

Validation

• Change type: UI / DB / routing
• Focused tests and category gates from the golden path
• npm run lint
• Reconciled with the current active release base; focused checks rerun afterward
• Production-code changes include a new or updated automated test in this PR

Tests Added Or Updated

• tests/unit/call-logs-ttft.test.ts
• tests/unit/shared/components/RequestLoggerV2.test.ts

Coverage Notes

• Covers src/lib/usage/callLogs.ts, open-sse/handlers/chatCore/attemptLogging.ts, and src/shared/components/RequestLoggerV2.tsx.
• Validates TTFT calculation, null persistence on failure, formatting thresholds, and table sort invariants.

Reviewer Notes

• Includes database migration 171_call_logs_ttft_ms.sql (additive nullable column, backward-compatible with existing call log records).

[diegosouzapw]

Thanks for this — TTFT visibility is genuinely useful. In reviewing the group we found
#13373 covers the same ground (identical ALTER TABLE call_logs ADD COLUMN ttft_ms
statement, same TTFT column in RequestLoggerV2) and goes further: it also fixes the
underlying TPS formula bug (wall-clock vs. generation-time) that affects thinking-model rows,
and threads the fix through getModelLatencyStats (auto-combo speed ranking) and the
playground, which this PR doesn't touch. To avoid a duplicate migration/column, we're
planning to move forward with #13373 and close this one as subsumed — flagging here first
in case there's something in requestLoggerMetrics.ts or the normalizeTtftMs edge-case
test worth porting over with credit before that happens.

Triage note: this is the review recommendation — the close itself happens only after the maintainer's per-PR sign-off (and, where a superseding PR is named, after it has landed). Nothing is being closed by this comment.