feat(project-router): native routing + drop invalid openrouter/free fallback

[JacobPEvans-personal]

What

Two related changes:

1. Project Router → native, no AI. project-router.yml now adds issues/PRs to the org board with actions/add-to-project@v1 instead of running claude-code-action against a custom prompt. The board exposes only Status and Phase fields (no Priority/Size/Type — the old prompt set fields that don't exist), so board membership is the only meaningful action. Items route only when they carry a type:* label (if: gate), preserving the original inclusion rule. .github/prompts/project-router.md deleted.
2. Drop the broken model fallback across the other 16 AI workflows: remove || 'openrouter/free' everywhere and collapse the phantom AI_MODEL_OPS/REVIEW/DOCS tiers (defined in no repo) to vars.AI_MODEL. Real tiers (CODE/ISSUES/PLAN) retained as overrides.

Why

docs / Project Router has failed 100% since ~2026-06-01: model resolved to the literal openrouter/free, which the docs OpenRouter key can't access. Root cause is the per-repo model-variable fan-out (only 5 repos) leaving other callers with nothing to inherit. The companion terraform-github PR makes AI_MODEL an org-level variable so every repo inherits a valid model — making the literal fallback both unnecessary and harmful. Routing via an LLM for what actions/add-to-project does deterministically was also unnecessary token spend.

⚠️ Prerequisite (auth)

The native router writes to an org Projects v2 board, which the default GITHUB_TOKEN cannot do. It mints an app token via actions/create-github-app-token@v3 (same pattern as the run-claude-code composite). The JacobPEvans-claude App must have organization Projects: write permission — please confirm/grant before relying on this. Without it, add-to-project 403s.

Sequencing

Merge after terraform-github#9 is applied and the org AI_MODEL variable is live. Otherwise callers without a repo-level var get an empty --model. (The native project-router itself has no model dependency, so the docs board failure is fixed regardless.)

Notes

• claude-review.yml is deprecated (disabled, if: false, marked for deletion). It only received the consistent one-line literal strip; its pre-existing actionlint findings (undeclared inputs in never-running jobs) are out of scope. Suggest a follow-up to delete it + its caller refs.

Verification done

• bun test: 147 pass / 0 fail.
• actionlint (run ad-hoc): changed workflows clean; only pre-existing findings in the deprecated claude-review.yml.
• No openrouter/free literal or phantom-tier ref remains (the only match is a doc comment example in smoke-test.yml).

Verification still needed (manual)

• Confirm the App has org Projects: write, then open a test issue with a type:* label in a calling repo and confirm it lands on Project chore: finalize v0.0.1 release #1 "Server Infrastructure" and that an untyped item does not.

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