add per-layer CI scripts and Gitea workflow (not activated)

ci/*.sh — shell-only, client-side-only so `git clone && make test`
works on any Linux or macOS dev box without network or shared state.
One script per testing layer so both Makefile targets and the CI
workflow can call them without duplicating logic. Rewrite of the
existing ci/test.sh to shell out to dart + flutter layers in one
pass (analyze, format, dart test, flutter test) plus five new
scripts for the other layers.

smoke_bundle.sh is the "tests passed but app doesn't start" gate
the user flagged: builds the Linux release bundle, runs it under
xvfb for 5s, fails on any non-SIGTERM exit — catches dynamic-linker
errors, missing-asset regressions, plugin-init crashes that widget
tests can't see.

.gitea/workflows/test.yml is a four-job pipeline (unit, integration,
startup-bundle, e2e) that shells out to the ci/*.sh scripts. NOT
activated — Gitea Actions has to be enabled in the instance settings
first. GitHub-Actions-compatible, so copying to .github/workflows/
is the whole migration if the repo moves.

Co-Authored-By: Claude <noreply@anthropic.com>

ci/test.sh

@@ -1,8 +1,20 @@
 #!/usr/bin/env bash
-# CI entry: run the full test matrix. Shells out to Makefile targets.
+# Fast test layer — unit + widget + golden. Runs in <60s on a warm
+# cache. Called from `make test` and the pre-push hook.
 set -euo pipefail
-
 cd "$(dirname "$0")/.."
 
-make test
-make test-integration
+echo "==> dart analyze (root package)"
+dart analyze
+
+echo "==> dart format (whole tree)"
+dart format --set-exit-if-changed .
+
+echo "==> dart test (root package)"
+dart test
+
+echo "==> flutter analyze (app)"
+(cd app && flutter analyze)
+
+echo "==> flutter test (app unit + widget + golden)"
+(cd app && flutter test)