ci(frontend): add react-doctor check for landing site (#151)

* ci(frontend): add react-doctor check for landing site

Adds a CI job that runs react-doctor (https://github.com/millionco/react-doctor)
against the Next.js 15 + React 19 landing site at frontend/src/landing/.
The landing has 29 .tsx components and no existing lint coverage; the only
prior frontend CI was a schema.ts drift check in go.yml.

- New workflow .github/workflows/react-doctor.yml, path-filtered to
  frontend/src/landing/** so backend-only PRs don't pay for it.
- doctor script + react-doctor devDep added to the landing package.
- Default --blocking=error: surfaces security, bugs, perf, a11y, and
  maintainability findings without failing CI on existing warnings
  (current baseline: 0 errors, 58 warnings, ~5s locally).
- Runs with --no-telemetry so CI runners don't ping react.doctor.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* ci(frontend): also scope react-doctor push trigger to landing paths

Mirrors the PR path filter on push to main so backend-only merges don't
re-run the landing check. Unlike go.yml/cli-e2e.yml (which trigger on
broad path sets), this workflow only cares about frontend/src/landing/.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* ci(frontend): use react-doctor GitHub Action, drop devDep + lockfile churn

Replaces the npm install + npm run doctor approach with the official
millionco/react-doctor@v2 composite action. The action manages its own
Node setup and react-doctor install on the runner, so the landing
package.json and lockfile stay untouched (no transitive-dep bloat from
react-doctor's 479-package tree).

The action also wires up sticky PR summary comments, inline review
comments, and commit statuses out of the box — requires pull-requests
and statuses write perms.

Author: harshitsinghbhandari

.github/workflows/react-doctor.yml

@@ -0,0 +1,32 @@
+name: React Doctor
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - "frontend/src/landing/**"
+      - ".github/workflows/react-doctor.yml"
+  pull_request:
+    paths:
+      - "frontend/src/landing/**"
+      - ".github/workflows/react-doctor.yml"
+
+permissions:
+  contents: read
+  pull-requests: write
+  statuses: write
+
+jobs:
+  doctor:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      # Composite action: installs react-doctor itself, runs the scan against
+      # the landing site, posts a sticky PR summary + inline review comments,
+      # and publishes a commit status. Default blocking=error means only
+      # error-severity findings fail the job; warnings are reported but don't
+      # block.
+      - uses: millionco/react-doctor@v2
+        with:
+          directory: frontend/src/landing