CI paths: Release Config Check — stop running on every PR #852

Part of #834. Phase 3. Blocked on #850.

What

release-config-check.yml triggers on every PR with no paths:. It validates putitoutthere.toml, so that file (and its own definition) is the entire trigger surface. Spec row 12.

Exact change

.github/workflows/release-config-check.yml — replace the on: block with:

on:
  pull_request:
    branches: [main]
    paths:
      - 'putitoutthere.toml'
      - '.github/workflows/release-config-check.yml'

Keep branches: [main]. Do not touch the check: job — its id is anchored as check-success ~= ^check / in .mergify.yml.

Expected checks on this PR

Files touched: .github/workflows/release-config-check.yml only.

MUST run

• Release Config Check (self-path)
• Conventions (all 8 lanes) — still unconditional until phase 4

MUST NOT run

• Python Test, TS Test, Rust Test, Plugins Test, Python Lint, Python Typecheck, TS Lint, TS Typecheck
• Release Precheck and Changelog Check if their slices already merged

This is the cleanest single observation in the whole epic: after this merges, a PR touching only putitoutthere.toml runs Release Config Check + Release Precheck and nothing else.

Acceptance

• CI paths: Mergify — gate each anchor behind the files it covers #850 merged to main first
• The PR's check list matches the groups above exactly
• Mergify Merge Protections green, with Release Config Check reported applied-and-satisfied
• Merge, close this issue

Notes

• The if in .mergify.yml for this workflow is an exact mirror of this paths: — the two must stay identical.
• No changelog fragment, no e2e attestation.