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.

docs/README.md

@@ -120,25 +120,6 @@ What gets sent: token symbol names (e.g. "ETH", "USDC"). No addresses, no
 balances, no identifying information. As with any request, CoinDesk sees your IP
 address.
 
-**Phishing domain blocklist** (`raw.githubusercontent.com`)
-
-A community-maintained list of phishing domains, used to warn you when a site
-that asks to connect, or to have a transaction or signature approved, is a known
-scam. A copy is bundled into the extension at build time, so the protection
-works before any network request happens. At runtime the extension fetches the
-live list to pick up newly added domains, keeping only the entries not already
-in the bundled copy (persisted locally if under 256 KiB). This endpoint is not
-user-configurable.
-
-When it is contacted: when the background script starts, if the last fetch was
-more than 24 hours ago, and every 24 hours after that. The time of the last
-fetch is remembered across browser and background restarts, so restarting does
-not cause a re-download. If a fetch fails, or the list is too large to keep, the
-extension waits an hour before trying again outside that 24-hour schedule rather
-than retrying on every restart. It is a plain download of a public file —
-nothing about you is sent, but the host sees your IP address. If the fetch
-fails, the bundled copy is still used.
-
 **Etherscan address labels** (`etherscan.io`; `sepolia.etherscan.io` on Sepolia)
 
 When you review a send, AutistMask fetches the recipient's public Etherscan
@@ -367,8 +348,12 @@ confirmation screen. It contains only addresses involved in fraud -- it is not a
 sanctions list.
 
 **Phishing domain warnings.** Sites asking to connect or to have something
-approved are checked against the phishing domain blocklist described under
-External Services, and flagged with a red banner if they match.
+approved are checked against a community-maintained list of known phishing
+domains, and flagged with a red banner if they match. The list is built into the
+extension: the check is entirely local, so nobody is told which sites you visit,
+and it works offline. It is also only as current as the release you are running
+— a domain added to the list upstream reaches you in the next version of the
+extension, not the same day.
 
 The first four filters can be individually disabled in Settings if you prefer to
 see everything unfiltered.