ci(ai-review): port Argus PR reviewer from adcp main

[bokelley]

Summary

Ports the Argus AI PR reviewer from adcontextprotocol/adcp to this repo. Two files:

• .github/workflows/ai-review.yml — the workflow (App-token mint, skip-on-trivial-resync, claude-code-action, posted-review verification, failure-comment fallback).
• .github/ai-review/expert-adcp-reviewer.md — the Argus prompt (voice + format unchanged; MUST FIX / coverage / triage adapted for this repo).

Uses IPR_APP_ID / IPR_APP_PRIVATE_KEY (shared with ipr-agreement.yml) plus ANTHROPIC_API_KEY to post reviews as the IPR bot, so they count toward branch protection.

Key adaptations vs upstream

Upstream (adcp main)	Ported (adcp-client-python)
Trivial paths: .changeset/*, mintlify-docs/*, static/schemas/cache/*, *.test.ts, package-lock.json	docs/*, examples/*, tests/*, test_*.py, *_test.py, src/adcp/types/generated_poc/*, src/adcp/types/_generated.py, CHANGELOG.md, schemas/*, llms.txt
MUST FIX: spec drift on static/schemas/source/**	Dropped — schemas are downloaded, not authored
MUST FIX: breaking wire change without major changeset	Replaced: breaking public-API change without conventional-commit ! / BREAKING CHANGE: (release-please semver signal)
MUST FIX: missing changeset on wire-touching PR	Dropped — repo uses release-please
MUST FIX: oneOf walker regression	Replaced: Pydantic discriminated-union regression (drops UnknownFormatAsset-style fallback, narrows additionalProperties, removes discriminator value)
(none)	Added: type-system layering breach — non-stable/aliases/_ergonomic modules importing from generated_poc/ or _generated.py, per CLAUDE.md
(none)	Added: CI gate regression — disabled tests, blanket # type: ignore, suppressed ruff rule
Coverage: schema-vs-docs coherence audit	Replaced with public-API coherence audit (breaking-change vs commit prefix, README/AGENTS.md/SKILL.md drift) and generated-type regeneration audit (confirm regen, not hand-edit)
Domain-expert triggers retargeted to src/adcp/types/** (non-gen), protocols/**, decisioning/**, migrate/**, mypy plugin → python-expert

Voice, sign-off ladder, decision tree, largest-file rule, test-plan-honesty rule, and the verify-posted / failure-comment steps are unchanged.

Test plan

• CODEOWNERS gate fires on this PR (changes touch .github/workflows/) — @bokelley approval required.
• After merge, the next non-draft PR triggers AI PR Review (Argus) and Argus posts a review as the IPR bot.
• Re-pushing a docs-only change to an already-approved PR triggers the Check for skippable re-run step and skips.
• Failure path: if the action exits without posting, the workflow leaves an ⚠️ Argus review could not complete comment on the PR.

🤖 Generated with Claude Code