docs(claude): correct enforced-guard claims and add the runtime dispatch rule

Fact-checked every line of CLAUDE.md against the tree. Six claims were wrong,
and two told an agent the opposite of the truth.

The file said nothing checks endpoints.ts against the Go routes and nothing
fails the build on a missing i18n key. Both guards exist and both run in
make verify: TestRouteRegistryContract diffs the real router against the
registry in both directions, and i18n-dead-keys.test.ts rejects a locale that
misses an en-US key as well as an en-US key nothing references. An agent
trusting the old text either skips a step it thinks is unenforced or is
blindsided when a "silent" omission turns the suite red.

The rest: the Go locale returns an empty string for an unknown key, not the raw
key; mtg-multi is a prebuilt binary fetched at build time, not a Go dependency
built from source; commits are type(area): summary, not <area>: summary, and
perf is in active use; make verify is the fast gate, not a mirror of CI, which
also runs race, vulncheck, a live-Postgres job where a SKIP is a failure, and a
fuzz smoke.

Add the five facts most likely to burn an agent, all reproduced before writing
them down. A fresh clone has no internal/web/dist, so go build dies on the embed
pattern while thirty-odd packages pass — it reads as a broken repo rather than a
missing make dist-stub. Every state-changing inbound/client op must dispatch
through runtime.Runtime; a direct xray/api.go call passes all local tests and
silently breaks every multi-node install, which is exactly what a hard rule is
for. Node 24 is required because make gen imports .ts directly. Postgres, xray
e2e and scale tests skip themselves without their env vars. An endpoint change
has a fourth step nothing checks: syncing docs/public/openapi.json.

Definition of done loses its first step — verify's gen-check already runs gen
and fails on a dirty generated diff.

docs/architecture.md

@@ -542,7 +542,7 @@ golangci-lint run                   # full lint (gofumpt + goimports formatting)
 go run main.go                      # run the panel locally (serves embedded dist if built)
 ```
 
-**Frontend (`cd frontend`, Node ≥ 22):**
+**Frontend (`cd frontend`, Node 24 — see `.nvmrc`):**
 ```bash
 npm install
 npm run dev          # Vite dev server on :5173; proxies API to Go backend on :2053 (run `go run main.go` too)