plan(v0.26): triage serve-filtering (#674) + release-vs-variant (#673)

[avrabe]

Triages the two actionable open feature requests into v0.26 as proposed requirements (planning lives in rivet, per release-planning), and corrects one stale status.

• REQ-253 (rivet serve further filter option  #674) — richer serve filtering (tags / field predicates / SQL). Reuse the existing s-expr filter engine and/or the gluesql rivet sql facade, not a serve-only filter language.
• REQ-254 (rivet release vs variant #673) — check a release against variant scope. Design-first: needs a DD on release ∩ variant semantics before implementation.
• REQ-251 (render_artifact_yaml allowlist drops fields_per_variant / Link.external / provenance.federation (latent data loss) #634) — corrected proposed → implemented, release v0.25.0 (the compile-time exhaustiveness guard shipped).

rivet validate → PASS, rivet docs check → 0 violations.

Refs: REQ-253, REQ-254, REQ-251

🤖 Generated with Claude Code

[github-actions]

⚠️ Performance Alert ⚠️

Possible performance regression was detected for benchmark 'Rivet Criterion Benchmarks'.
Benchmark result of this commit is worse than the previous benchmark result exceeding threshold 1.20.

Benchmark suite	Current: ea6234e	Previous: f3c0e93	Ratio
store_insert/10000	20574820 ns/iter (± 1767800)	12136780 ns/iter (± 298062)	1.70
link_graph_build/10000	58730114 ns/iter (± 6655538)	23467162 ns/iter (± 397068)	2.50
diff/10000	12658788 ns/iter (± 1143474)	8454617 ns/iter (± 760072)	1.50

This comment was automatically generated by workflow using github-action-benchmark.

[github-actions]

📐 Rivet artifact delta

Change	Count
Added	2
Removed	0
Modified	1
Downstream impacted (depth ≤ 5)	0

Graph

graph LR
  REQ_251["REQ-251"]:::modified
  REQ_253["REQ-253"]:::added
  REQ_254["REQ-254"]:::added
  classDef added fill:#d4edda,stroke:#28a745,color:#155724
  classDef removed fill:#f8d7da,stroke:#dc3545,color:#721c24
  classDef modified fill:#fff3cd,stroke:#ffc107,color:#856404
  classDef overflow fill:#e2e3e5,stroke:#6c757d,color:#495057,stroke-dasharray: 3 3

Loading

Added

• REQ-253
• REQ-254

Modified

ID	Changes
REQ-251

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_{Posted by rivet-delta workflow. The graph shows only changed artifacts; open the HTML dashboard (above) for full context.}