build: run the browser e2e suites in CI (closes #259)

Nothing automatic ran either e2e suite, so every browser-level guarantee in this
wallet -- WebAssembly under the shipped CSP, the recovery-phrase and private-key
DOM wipes, the ConfirmTx spend gate, the dApp approval round trips -- held only
when a human or an agent remembered to run it by hand.

.gitea/workflows/e2e.yml adds two jobs, e2e-chrome and e2e-firefox, one per
browser so a Chrome failure cannot hide the Firefox result. They are separate
from the check workflow: REPO_POLICIES.md caps make test at 20 seconds and
script/cibuild is a docker build whose Dockerfile runs make check, so neither the
cap nor the local fast path is touched. make check is byte-for-byte unchanged.

Neither suite could run on the runner as it stood, and the reason is not
docker-in-docker. The runner executes a job inside a container against the HOST's
docker daemon, and the job's checkout lives on a docker volume rather than a host
path, so `docker run -v "$PWD:/work"` is resolved by the host, silently succeeds
and mounts an empty directory -- measured on this runner. The runner image's node
is also too old to install this repo's dependencies. Both suites therefore ship
the repo to the daemon as a build context and build the extension inside the
pinned image, which leaves docker as the only prerequisite on a runner or a
laptop. The suites themselves are unchanged; only how the repo reaches the
container is.

Both scripts now build with --iidfile and run the image by ID rather than by tag,
so two clones running a suite at once on the same host cannot swap it under each
other.

The jobs report, they do not gate. Whether a check blocks a merge is Gitea branch
protection, which this repo does not configure, so a failure is a red mark a
reviewer must account for. Nothing can pass vacuously: no continue-on-error, no
`|| true`, and both scripts exit non-zero when docker is missing, when the image
build fails and when the browser fails to start.

script/test-e2e

@@ -7,17 +7,29 @@
 # caps make test at 20 seconds and a browser suite does not fit. Run it
 # yourself before touching popup views; it is the only check that can see
 # a used-but-not-imported identifier blow up at runtime.
+# .gitea/workflows/e2e.yml also runs it on every push, in a job separate
+# from check so that cap and the local fast path both stay intact.
+#
+# Docker is the only prerequisite. The repo reaches the container as a
+# build context and the extension is built inside it (see
+# tests/e2e/Dockerfile), so nothing here depends on the node, yarn or make
+# on the machine that starts the run. That is not a convenience: a bind
+# mount cannot work under Gitea Actions, and the runner image's node is too
+# old to install this repo's dependencies.
 set -eu
 
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
-# mcr.microsoft.com/playwright:v1.56.0-noble, 2026-08-09
-#
-# The playwright-core devDependency is pinned to the matching Playwright
-# version (1.56.0) and the two must be bumped together: the browsers ship
-# inside this image, and playwright-core looks for the exact browser
-# revision its own version expects. A mismatch fails at launch.
-IMAGE="mcr.microsoft.com/playwright@sha256:35246d87a7c88ea9b771c65d33171b2611b02a8253b4b12ce6f94376c55f99f2"
+IMAGE="$("$SCRIPT_DIR/projectname")-e2e-chrome"
+
+IIDFILE=""
+
+cleanup() {
+    if [ -n "$IIDFILE" ]; then
+        rm -f "$IIDFILE"
+    fi
+}
 
 main() {
     cd "$ROOT"
@@ -27,14 +39,23 @@ main() {
         exit 1
     fi
 
-    echo "Building extension for e2e..."
-    yarn run build 2>&1
+    IIDFILE="$(mktemp)"
+    trap cleanup EXIT
+    trap 'cleanup; exit 130' INT TERM
+
+    echo "Building the Chrome e2e image (extension included)..."
+    docker build --iidfile "$IIDFILE" -t "$IMAGE" -f tests/e2e/Dockerfile .
 
     echo "Running e2e suite in the pinned Playwright container..."
+    # The image is run by ID, not by tag: where two clones of this repo run
+    # the suite at once, the other build can move the tag between this
+    # build and this run, and the suite would then silently test the other
+    # checkout.
+    #
     # --ipc=host: Chromium's shared-memory needs more than the default
     #   64MB /dev/shm or renderers crash.
-    # --user: keep files the suite touches owned by the caller, not root.
-    # HOME=/tmp: the mapped uid has no home directory in the image.
+    # HOME=/tmp: the image's root home is not a reliable place for the
+    #   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
@@ -51,13 +72,10 @@ main() {
     #   on a deliberate bump.
     docker run --rm \
         --ipc=host \
-        --user "$(id -u):$(id -g)" \
         -e HOME=/tmp \
         -e PW_EXPERIMENTAL_SERVICE_WORKER_NETWORK_EVENTS=1 \
         -e "E2E_TRACE_NETWORK=${E2E_TRACE_NETWORK:-0}" \
-        -v "$ROOT:/work" \
-        -w /work \
-        "$IMAGE" \
+        "$(cat "$IIDFILE")" \
         node tests/e2e/run.js
 }