chore(changelog.d): prune 7 stale fragments + rewrite 2 misleading ones

[lusoris]

Summary

Hygiene cleanup of changelog.d/ per final-area sweep. Seven fragments
under changelog.d/fixed/ advertised behaviour that is no longer on
master and would have generated misleading release notes. Two
changelog.d/changed/ fragments contradicted the actual master state.

Deleted (7 — stale)

• changelog.d/fixed/vif-arc-mesa-anv-int64-reduction.md — Vulkan
  backend dropped per ADR-0726 (no core/src/feature/vulkan/ on master).
• changelog.d/fixed/vulkan-vif-fp64-g-computation.md — same.
• changelog.d/fixed/motion-vulkan-1067-regression.md — same.
• changelog.d/fixed/dispatch-strategy-pr1067-regression.md —
  references a g_hip_features[] table that never landed on master
  (HIP dispatch_strategy.c is still the ADR-0212 stub returning 0);
  Metal half of the bullet is superseded by ff4c30d40c.
• changelog.d/fixed/metal-dispatch-strategy-key-restore.md —
  references PR chore(deps): Update module github.com/getkin/kin-openapi to v0.144.0 [SECURITY] #1088 / chore(deps): Update Python (patch) #1104 from a fork-history with no landing
  commits on master; canonical Metal dispatch names were fixed by
  ff4c30d40c already in the changelog under
  metal-dispatch-key-mismatches.md.
• changelog.d/fixed/float-ansnr-enable-chroma-pr947-restore.md —
  float_ansnr extractor was removed by PR feat(core): drop legacy ansnr feature (pre-VMAF, never Netflix-adopted) #38 per ADR-0749 (grep -r float_ansnr core/ returns nothing).
• changelog.d/fixed/hip-ansnr-memcpy-direction.md — same; no
  core/src/feature/hip/float_ansnr_hip.c on master.

Rewritten (2 — contradictory)

• changelog.d/changed/onnx-blobs-to-github-releases.md — described
  the ADR-0457 offload as if complete. The fetcher script
  (scripts/ai/fetch-tiny-blobs.sh) is in place but transnet_v2.onnx,
  fastdvdnet_pre.onnx, lpips_sq.onnx are all still tracked in git
  (git ls-files model/tiny/*.onnx confirms). Rewritten to describe
  the actual scaffold-only state.
• changelog.d/changed/cuda-extractor-cambi-and-ssim-promotion.md —
  claimed cambi_cuda segfaults on every input (Issue fix: 12 medium/low round-3 bundle — SYCL ceiling, meson conflicts, CLI bounds, y4m, fuzz, motion debug, docs #857). That
  SIGSEGV was fixed by PR fix: 5 Fable deep-hunt findings — integer_ssim AVX2 16-bit overflow, bpc validation, set_fex UAF, vmafx-server DoS cap, CUDA prev_ref #866 + PR fix(codeql): CodeQL Python note-level cleanup (unused imports, lambdas, empty-except) #870 on 2026-05-16; Issue fix: 12 medium/low round-3 bundle — SYCL ceiling, meson conflicts, CLI bounds, y4m, fuzz, motion debug, docs #857 is
  closed (docs/state.md). Rewritten to drop the contradiction while
  preserving the truth that K150K still routes cambi through the CPU
  residual.

Added

• changelog.d/changed/changelog-d-stale-fragments-cleanup.md —
  documents this cleanup.

ADR-0108 deliverables checklist

• (1) Research digest — no digest needed: trivial (changelog-only hygiene; no code paths affected).
• (2) Decision matrix — no alternatives: only-one-way fix (stale fragments must be removed; misleading ones must be rewritten).
• (3) AGENTS.md invariant note — no rebase-sensitive invariants (changelog fragments are fork-local artifacts; never upstream-mirrored).
• (4) Reproducer / smoke-test command — git ls-files model/tiny/*.onnx confirms blobs still inline; find core -path '*vulkan*' -o -name 'float_ansnr*' confirms removed surfaces; bash scripts/release/concat-changelog-fragments.sh renders cleanly.
• (5) changelog.d/<section>/<topic>.md fragment — changelog.d/changed/changelog-d-stale-fragments-cleanup.md.
• (6) docs/rebase-notes.md entry — no rebase impact: changelog.d/ fragments are fork-local artifacts only; upstream Netflix/vmaf has no changelog.d/ tree.

Test plan

• pre-commit run passes against all touched files
• bash scripts/release/concat-changelog-fragments.sh runs without error after the deletions
• git grep confirms no remaining inbound references to the deleted fragment paths
• CI required-checks aggregator green

🤖 Generated with Claude Code