[johnnyhuy]

Part of #84
Closes #118

What changed: the landing page now has a hero section with the showcase value prop, a portal screenshot and clear calls to action into the demo. The primary button goes to /showcase and the secondary button goes to /catalog. The page is wired at a new /landing route in packages/app/src/App.tsx. The screenshot asset lives at packages/app/public/portal-showcase.png and is referenced with a root-relative path.

The visual treatment is provisional: bold type, thick borders and hard offset shadows, in the spirit of the Gumroad direction in #84. It uses theme tokens so it adapts to light and dark mode and can be restyled without touching the structure.

How it was verified:

• mise run lint - passed (packages/backend 1 file, permission module 3 files, theme 1 file, plausible 8 files, packages/app 51 files, no errors)
• mise run test - passed: 6 suites passed, 1 skipped, 34 tests passed, 1 skipped. New tests in LandingPage.test.tsx: renders the hero headline and value prop, links the primary call to action into the showcase, links the secondary call to action into the catalog, shows the portal screenshot with alt text. Baseline after test: add component tests for showcase page and cards #117 was 30 passed, 1 skipped in 5 suites, so this adds 4 passing tests.
• mise run dev - frontend on localhost:3000 returned 200 and the backend responded on localhost:7007. Signed in as guest, opened /landing, and the page rendered the hero, both calls to action and the portal screenshot.
• mise run build (Docker image) was not run. No backend code or packaging changed.

Proof:
Capture method (a) screenshot succeeded this run. Full page PNG of /landing signed in as guest, saved at .tmp/proof/landing-hero.png on this branch: https://github.com/echohello-dev/backstage/blob/agent/issue-118-landing-hero/.tmp/proof/landing-hero.png

Capture method (b) test output is listed in the verification above.

Reviewer notes and known gaps:

• The route sits at /landing and nothing links to it yet. Where the landing page should live (replacing the home page at /, or staying a separate route wired into the sidebar) is a call for Johnny, along with the final look. The hero structure is ready for either choice.
• The remaining landing sections from Ship public showcase landing page with Gumroad-style direction #84 (feature highlights, footer) are follow-up slices.
• The parent epic Ship public showcase landing page with Gumroad-style direction #84 stays open.