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>

.agents/context/assertion-removals.md

@@ -0,0 +1,26 @@
+# Assertion removal ledger
+
+`scripts/verify.mjs` may only lose an assertion by adding an entry here. The
+gate counts the `## ` headings in this file and allows exactly that many
+removals below the recorded floor — so a reduction is impossible without a
+written reason landing in the same commit, as a visible diff.
+
+Adding an entry is not a formality. An assertion pins a real contract; removing
+one means that contract is now unverified. Say where it moved, or say plainly
+that nothing checks it any more.
+
+## vote-service one-vote-per-IP contract
+
+**Removed:** 2026-09-06, when `vote-service/` was taken out of this repository.
+
+**What it asserted:** that `vote-service/main.go` contained both
+`X-Forwarded-For` and `one active vote per skill` — the review desk's only
+anti-abuse control, one vote per visitor enforced server-side by source IP.
+
+**Why it went:** there is no file left to read. The check was a substring match
+against source that now lives elsewhere.
+
+**Where it must be re-asserted:** in whichever repository holds the service. The
+deployed service still enforces the contract; nothing in this repository proves
+it. If `vote-service/` ever comes back here, restore the assertion and delete
+this entry.