chore: re-vendor canonical files from prompts at dd4027b (closes #472)

Copies .dockerignore, .gitignore, .prettierignore, check.yml and
REPO_POLICIES.md from sneak/prompts at dd4027b. The repo's own entries
(dist/, release/, yarn files) are kept after the canonical content.

The Dockerfile gets separate lint and test phases. Its last stage
depends on both, checks the git describe version and runs make build.
script/lint, test, check, cibuild and docker are the canonical models.
check-censored moves into the lint phase and test-verify-build into the
test phase. fmt and fmt-check fall back to the nvm-installed node. The
e2e image builds are uncached. Comments that cited the old test caps
now say 60 seconds, and comments that named what runs a script now name
the Dockerfile phase or stage.

Model: opus-5-5

tests/phishingDomains.test.js

@@ -45,9 +45,9 @@ describe("vendored blocklist", () => {
         // than loudly, so the ordering the search depends on is asserted here
         // against the committed file rather than assumed of the generator.
         // One assertion at the end rather than one per entry: 100k+ expect()
-        // calls cost seconds, and make test is capped at 30 for the whole
-        // suite. The index of the first offender is reported, so a failure
-        // still says where.
+        // calls cost seconds, and make test is capped at 60 seconds for the
+        // whole suite. The index of the first offender is reported, so a
+        // failure still says where.
         let previous = "";
         let outOfOrderAt = -1;
         for (let i = 0; i < vendored.count; i++) {