release: 0.7.0 — AI gateway extensions (ADR-0024 + ADR-0030)

[ndreno]

Summary

Cuts the 0.7.0 release. The headline is the AI gateway milestone: caller-owned model, glob-based dynamic routing, stateless Responses API, aggregated /v1/models, four policy middlewares, and CEL extensions.

• Workspace version: 0.6.3 → 0.7.0 (single bump; all crates inherit via version.workspace = true; internal path-deps updated to match).
• CHANGELOG: cut [Unreleased] → [0.7.0] - 2026-05-05, consolidate the three scattered ### Added blocks into thematic subsections, fill in the stale comparison links from v0.4.1 forward.
• Docs: bump the pinned plugin URL example in spec-configuration.md to v0.7.0.

Why 0.7.0 and not 0.6.4

The ai-proxy model: removal (ADR-0030 §0) is a breaking change in pre-1.0. SemVer says minor bump, and the migration is mechanical — both vacuum:barbacane lint and the runtime serde(deny_unknown_fields) reject leftover model: with a clear error pointing at the offending block.

Release readiness

• ✅ 110 unit tests in ai-proxy, 56 in cel, 22 end-to-end integration tests covering every concrete ADR-0030 claim
• ✅ Vacuum ruleset has invalid-ai-proxy-leftover-model.yaml guarding the breaking-change lint
• ✅ Spec fragment has test_shipped_ai_gateway_spec_fragment_compiles regression test
• ✅ cargo fmt --all --check, cargo clippy --workspace --lib --bins, cargo test --workspace --exclude barbacane-test, cargo deny check advisories — all clean

Known deferred items (documented in changelog and roadmap)

• Stateful Responses API (previous_response_id, GET /v1/responses/{id}) — explicit 400 with forward-compat hook
• Streaming SSE re-encoding for Responses synthetic ids — workaround documented (drop stream: true)
• /v1/models caching / single-flight — endpoint off the data-plane critical path
• Anthropic chat-completion streaming — buffered with warning log (pre-existing)

Test plan

• cargo fmt --all --check clean
• cargo clippy --workspace --lib --bins clean
• cargo test --workspace --exclude barbacane-test --release — all passing
• cargo deny check advisories — advisories ok
• CHANGELOG comparison links resolve against the GitHub UI (verified format)
• Tag v0.7.0 after merge
• Release workflow builds and publishes plugin .wasm assets to the v0.7.0 GitHub release