feat: vendor and censor the phishing blocklist at build time (closes #219)

The blocklist URL in shipped code named a competitor and pointed at a moving
ref, and the extension re-fetched from it every 24 hours, which also meant a
third party decided what this wallet warns about. All of that is gone.

script/vendor-blocklist fetches upstream at a pinned commit, verifies the
sha256 of the bytes that commit serves, and writes
src/shared/phishingBlocklist.json. It is build-time tooling, never shipped, and
the one place in the repo that names the upstream project; a source reference
nobody can verify is not a source reference.

The artifact stores truncated sha256 digests rather than domain names. That is
what censors it: the previous file contained the competitor's name 6,475 times,
as phishing domains impersonating them, and not one of those domains is
dropped. It also makes lookups a binary search over a fixed-width string, so
nothing is built at module load — which matters on MV3, where the worker
re-evaluates the module on every wake — and takes the file from 8.7 MB to
1.7 MB.

script/check-censored enforces the rest: it reads the name out of the vendoring
script rather than repeating it, and fails on any occurrence in the working
tree or under dist/ that is not one of the two literals shipped code cannot
avoid. It runs in make check, which inspects dist/ when there is one and says
loudly when there is not, and again with --require-dist at the end of every
make build.

Removing the runtime fetch retires the delta, the extension-storage persistence
and the 24-hour alarm from #158. A retired alarm is now cleared rather than
left waking the worker forever on installs that already have it.

The e2e suite drives the warning end to end from a real blocklisted origin
served as a real http(s) site, with a control asserting the banner stays hidden
for one that is not listed. Its service-worker interception canary needed a new
anchor, since the startup fetch it used to watch for no longer happens: it now
wakes the worker with a message and asks it for one throwaway fetch.

LICENSE no longer cites a repository that returns 404.

eslint.config.js gains one block: script/lib/ holds node programs the shell
entrypoints call, and without it they lint with no globals at all.

script/test-e2e

@@ -59,12 +59,12 @@ main() {
     #   browser profile.
     # PW_EXPERIMENTAL_SERVICE_WORKER_NETWORK_EVENTS=1: without it,
     #   ctx.route() intercepts page requests only, and every fetch made by
-    #   the MV3 background service worker — including the phishing
-    #   blocklist fetch that src/background/index.js issues at worker
-    #   startup — goes to the real internet. The flag is experimental and
-    #   Playwright may drop or rename it. It cannot break silently: the
-    #   harness probes service-worker interception at launch and aborts
-    #   the whole suite if it is not in effect (see the interception
+    #   the MV3 background service worker — the JSON-RPC calls behind
+    #   every approval the suite drives among them — goes to the real
+    #   internet. The flag is experimental and Playwright may drop or
+    #   rename it. It cannot break silently: the harness asks the worker
+    #   for one request of its own at launch and aborts the whole suite
+    #   if it does not reach the route handler (see the interception
     #   canary in tests/e2e/harness.js). If a future Playwright removes
     #   the flag, that probe is what will fail, and the fix is either a
     #   replacement mechanism or an honest downgrade of the isolation