chore: rename .svu.yaml to .svu.yml so svu reads it

[bketelsen]

svu reads only .svu.yml; std's config lived at .svu.yaml and was silently ignored. Renamed it without changing its contents, and updated the current-path references in AGENTS.md, docs/design/overview.md, docs/org-adrs.md, docs/specs/pr-review-rubric.md, the PR template, the review prompt, and the protected path in policies/agent-governance.json. Left alone: accepted ADR-0001, which is immutable history; the core-synced .agents/skills/frostyard-go-repo/SKILL.md; and the historical clix plan.

svu 3.4.1 svu next gives v0.2.3 both before and after the rename, and v0.2.3 again with always: false. There are fix commits and no feat or breaking commits since v0.2.2, so the next release is unchanged today. The rename makes v0: true and always: true take effect in future. No tag or release was made. Checks: git diff --check is clean, check-docs is green, and no Go files changed.

Reviewed by github-copilot/gpt-6-sol.

Review

approve after 1 round: The previous blocker is resolved: accepted ADR-0001 again preserves the historical .svu.yaml reference. The config is renamed without content changes, current-path references and the protected governance path match .svu.yml, and the diff contains no unrelated changes. git diff --check is clean.

Approved plan

Assumptions (brainstormed alone)

• svu reads only .svu.yml (per request); verified empirically by comparing svu next before/after.
• Current settings (prefix v, mode all, always: true, v0: true, log.directory ".") suit std: v0 keeps breaking changes on 0.x (latest tag v0.2.2); always guarantees a bump even with only non-conventional commits. None are wrong for this repo, so contents stay unchanged.
• Single tiny task; executed directly (executing-plans), one reviewer pass.

Task 1: rename

1. In the plan worktree: record svu next and svu current output (before).
2. git mv .svu.yaml .svu.yml; confirm git ls-files '*.svu.yaml' is empty and grep repo for .svu.yaml references (Makefile, docs, AGENTS.md) and update any found.
3. Record svu next (after); explain difference (expected: always forces at least a patch bump when HEAD has no feat/fix commits since v0.2.2; v0 prevents a 1.0.0 jump on breaking commits).
4. Do NOT run make bump, tag, or release.

Verification

• git diff --check; gofmt check (no Go changes).
• git status shows only the rename (plus any reference updates).

Proposal

onionsoup_propose_changes with item, summary containing before/after svu next outputs and explanation.

Plan approved by bjk.

Work item: w-request-r-20260928-36780e