Freeze the final repaired 0.16.3 calibration

[TheGreenCedar]

This freezes the final 0.16.3 runtime constants after all support PRs, including #1581, #1622, and the cross-run release-closeout repair #1630, were integrated into dev/codestory-next.

What changed

The PR's net source diff is one file:

• crates/codestory-llama-sys/per-user-embedding-server-constant-set.json

Calibration source 35efd4f08b6cc544dee11270fee3d61b28fd16a1 restored that file to the canonical unfrozen input. Protected macOS Metal calibration run 30598888717 generated the frozen file now committed at fba7dbdde7ec533188f84f3d3d63934f732d3782. No workflow or product source changed after calibration.

Evidence

• Focused draft source, Linux contracts, rustdoc, workflow-policy, and calibration self-tests passed.
• Calibration-source hostile mutations and the Windows native probe passed in run 30598710638.
• The sole calibration run 30598888717 passed in 3m04s: macOS Metal only, three fresh server generations, one sample per metric, no CPU or qualification lane.
• The generated constant set is byte-identical to artifact embedding-calibration-bundle-35efd4f08b6cc544dee11270fee3d61b28fd16a1 and is the only path changed from its calibration source.
• Deterministic selection and calibration-release lineage validation passed.
• Frozen-candidate hostile mutations and the Windows native probe passed in run 30599143120.
• The one broad exact-head source proof is run 30599340822; frozen-candidate qualification follows only if it passes.

Risk and rollback

The runtime constants are bound to the authenticated calibration source and bundle. Any later source or workflow commit invalidates this candidate. Rollback is the prior constant set; it cannot be mixed with this candidate's proof receipt or calibration bundle.

Closes #1631
Refs #1179