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.

Makefile

@@ -1,4 +1,4 @@
-.PHONY: bootstrap setup install test test-e2e test-e2e-firefox lint fmt fmt-check check docker hooks build build-debug verify-build clean dev
+.PHONY: bootstrap setup install test test-e2e test-e2e-firefox lint fmt fmt-check check check-censored docker hooks build build-debug verify-build vendor-blocklist clean dev
 
 # Standard targets are thin shims; the implementations live in script/
 # per the scripts-to-rule-them-all pattern (see the Entrypoints section
@@ -35,6 +35,12 @@ fmt-check:
 check:
 	@script/check
 
+# Assert that the competitor name appears nowhere but its documented
+# exceptions. Part of check, and re-run against dist/ at the end of a build;
+# separate target for re-running it alone.
+check-censored:
+	@script/check-censored
+
 docker:
 	@script/docker
 
@@ -45,6 +51,7 @@ build:
 	@echo "Building extension..."
 	@yarn run build 2>&1
 	@script/verify-build
+	@script/check-censored --require-dist
 
 # Development-only build: enables the red DEBUG / INSECURE banner and makes
 # the hardcoded test recovery phrase the output of wallet creation. Never
@@ -53,12 +60,19 @@ build-debug:
 	@echo "Building extension (DEBUG)..."
 	@AUTISTMASK_DEBUG=1 yarn run build 2>&1
 	@AUTISTMASK_DEBUG=1 script/verify-build
+	@script/check-censored --require-dist
 
 # Assert the compiled DEBUG state of the bundles already in dist/. Runs at
 # the end of build and build-debug; separate target for re-running it alone.
 verify-build:
 	@script/verify-build
 
+# Refresh src/shared/phishingBlocklist.json from its hash-pinned upstream.
+# Run deliberately, land the diff: the extension does no runtime fetching, so
+# the shipped list is as fresh as the last vendoring run that was released.
+vendor-blocklist:
+	@script/vendor-blocklist
+
 clean:
 	@rm -rf dist/