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 three literals shipped code cannot
avoid — two provider-shim identifiers in src/content/inpage.js and one ERC-20's
on-chain name in src/shared/tokenList.js. Each is permitted only at the path
that carries it, and at the emitted paths that path is bundled into, so a
literal appearing anywhere else fails like any other occurrence. 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.

LICENSE

@@ -682,7 +682,14 @@ under their own licenses. They are NOT covered by the GPL-3.0 license above.
 
 ---------------------------------------------------------------------------
 File: src/shared/phishingBlocklist.json
-Source: https://github.com/AugurProject/eth-phishing-detect (config.json)
+Source: the eth-phishing-detect community blocklist (src/config.json).
+        The file here is derived from it, not a copy of it: only the
+        blacklist is carried over, and each entry is stored as a truncated
+        digest rather than a domain name. script/vendor-blocklist records
+        the exact upstream URL, the commit it is pinned to and the hash of
+        the bytes that commit serves, and is what regenerates this file.
+        The URL previously cited here, under a different organisation,
+        returns 404: that repository is gone.
 Copyright: Copyright (c) 2018 kumavis
 License: Don't Be a Dick Public License (DBAD), Version 1.2
 ---------------------------------------------------------------------------