chore: take vote-service out of the repository root

Removes the Go source, Dockerfile, go.mod, and Kubernetes manifests. The
deployed service is untouched and the review desk still calls it over
window.SKILLS_REVIEW_VOTE_API; only the source leaves.

The runbook does not leave. vote-service/README.md moves to
docs/vote-service.md, because it carries the parts that are hard to
rediscover: why the ingress overwrites X-Forwarded-For and Caddy stamps
X-Client-IP instead, why the image is side-loaded into containerd rather
than pulled, and why the PVC pins the Deployment to one node.

This drops verify.mjs from 84 assertions to 83. The removed one read
vote-service/main.go for X-Forwarded-For and 'one active vote per skill'
-- the review desk's only anti-abuse control -- and there is no file left
to read. It is the first assertion this repository has ever lost.

Rather than lower the gate's floor and leave a bare number behind,
gate.sh now subtracts the number of entries in
.agents/context/assertion-removals.md from the baseline. A removal costs
a written reason in a tracked file, in the same commit, as a visible
diff. Tested at 82 assertions: still refused.

Also drops the 22 MB of PNG baselines under .agents/snapshots/before/ and
before-reduced-motion/. They pictured the hand-written site, which no
longer exists; visual-regression.mjs has no compare mode to diff them
against; and they are recoverable from d88d8b8.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

plans/astro-refactor/HANDOVER.md

@@ -36,8 +36,11 @@ consolidation is not proven visually yet.
 
 **03 — verification net (Codex).** `.agents/scripts/visual-regression.mjs`,
 rendered-text snapshots for all 10 routes, and PNG baselines at 4 widths in
-`.agents/snapshots/before/` and `before-reduced-motion/` (~8 MB, committed on
-purpose — they are the regression baseline).
+`.agents/snapshots/before/` and `before-reduced-motion/`. Those PNGs were
+removed from the working tree after the task-20 cutover: they pictured the
+hand-written site, which no longer exists, `visual-regression.mjs` has no
+compare mode to diff them against, and they were 22 MB.
+`git show d88d8b8:.agents/snapshots/before/` still has them.
 
 **04 — content schema (MiniMax).** `src/content/config.ts` with eight empty
 collections and a strict `localized({en, pt})` helper. No content moved; that is