chore(quality): reconcile final v3.8.50 ratchets

[diegosouzapw]

Summary

• reconcile the v3.8.50 closing bundle-size measurement from 7666 to 8045 gzip bytes
• freeze the two exact file-size drifts at their measured release-tip values
• record source attribution and validation evidence directly beside each baseline
• keep all ratchets direction-down and blocking from the new exact values

Evidence

Measured on release/v3.8.50@e0ce95c592 after #9835:

• release-green quick/hermetic: 0 HARD failures; one file-size drift before this PR
• bundle-size: 8045 (reproduced); prior baseline 7666
• per entry: omniroute 4380/15000, MCP 1195/5000, Node runtime 887/8000, reset-password 1583/6000
• file-size: src/sse/handlers/chat.ts 1918 vs 1904 and open-sse/translator/response/openai-responses.ts 1215 vs 1204
• dead-code: 227/227

Attribution:

• chat.ts growth is feat(guardrails): modality bridge core — vision mode/task-aware/cache/input_image + modalityBridge settings #9759 Modality Bridge request-pipeline wiring, covered by the Vision Bridge canaries/focused suite
• openai-responses.ts growth is fix(api): streamed Responses tool arguments bypass null-omission normalization (#6951 follow-up) #9168 argument-delta buffering/normalization, covered by dedicated translator regressions
• bundle growth is accumulated legitimate v3.8.50 CLI/runtime work; every entry remains far below its absolute budget

Validation

• npm run check:file-size — pass
• npm run check:bundle-size -- --ratchet — 8045/8045 pass
• bundle/file-size/repro focused tests — 39/39 pass
• JSON parse and git diff --check — pass

Closes #9737

[diegosouzapw]

Final pre-merge audit complete after the Vietnamese base-red repair:

• head: ec2767b0fdc5f0610f27a3e081f50518be191ec3
• base: release/v3.8.50 at 4d8506c2c57b2f59073a3bc724da3b233cf63f23
• distance: 0 commits behind
• blocking checks: 0 (Build (advisory) is the only pending check and is non-blocking by protocol)
• unresolved, non-outdated review threads: 0
• CI: all four unit shards, Vitest, Fast Quality, ESLint, docs, merge integrity, CodeQL, DAST, Semgrep, and Fast Production Build green
• local ratchets: bundle 8045/8045; dead-code 227/227; file-size green; 71/71 focused ratchet tests green

Owner authorized merge; applying the fused release freeze gate.