feat: phase 1 public site skeleton — layout, routes, CSS, logo pipeline

Ship base Jinja layout (header/nav/main/footer with skip link and aria-current),
mobile-first single-file CSS using the ROADMAP palette tokens, and four public
routes: /, /about, /contact, /shop. Blog index renders via a stable
PostService.list_published() stub returning [] — Phase 2 only swaps the body.
About is static placeholder copy, /contact ships an inert form plus a mailto:
link driven by ADMIN_CONTACT_EMAIL, /shop shows a "Coming soon" card.

Adds a Pillow-based scripts/generate_static_assets.py producing resized logo
PNG + WebP, multi-size favicon.ico, and a 180x180 apple-touch-icon on a cream
background. Outputs committed for a reproducible build.

Also ship docs/MANUAL_TESTING.md with per-route / responsive / a11y / static-
asset checklists, and mark Phase 1 complete in docs/ROADMAP.md.

tests/test_public_routes.py

@@ -0,0 +1,103 @@
+"""Smoke tests for the public-site skeleton routes.
+
+These tests focus on contract rather than styling:
+
+- every public route returns 200 with an HTML content-type
+- each page contains a page-specific substring (proves the template
+  actually rendered, not just that the route exists)
+- the homepage renders the empty-state copy when PostService returns []
+- the shared layout emits the logo image path so nav/logo aren't broken
+  by a future refactor
+
+No mocks of the DB (there is no DB in Phase 1). The PostService stub
+already returns an empty list, which is exactly what we want to assert
+against.
+"""
+
+from __future__ import annotations
+
+import pytest
+from fastapi.testclient import TestClient
+
+from app.main import app
+
+
+@pytest.fixture(scope="module")
+def client() -> TestClient:
+    """Return a module-scoped FastAPI TestClient.
+
+    TestClient uses the module-level `app` built by `create_app()` at
+    import time, i.e. the exact same app uvicorn runs in production.
+    """
+    return TestClient(app)
+
+
+@pytest.mark.parametrize(
+    "path,expected_substring",
+    [
+        ("/", "Chicken Babies"),
+        ("/about", "About the farm"),
+        ("/contact", "Get in touch"),
+        ("/shop", "Coming soon"),
+    ],
+)
+def test_public_route_renders_html(
+    client: TestClient,
+    path: str,
+    expected_substring: str,
+) -> None:
+    """Every public page returns 200 HTML containing a page-specific string.
+
+    The substring is intentionally a headline the template owns so the
+    test fails loudly if the wrong template is accidentally wired up.
+    """
+    response = client.get(path)
+
+    assert response.status_code == 200, (
+        f"{path} returned {response.status_code}: {response.text[:200]}"
+    )
+
+    content_type = response.headers.get("content-type", "")
+    assert content_type.startswith("text/html"), (
+        f"{path} returned unexpected content-type: {content_type!r}"
+    )
+
+    assert expected_substring in response.text, (
+        f"{path} body missing expected substring {expected_substring!r}"
+    )
+
+
+def test_home_shows_empty_state_when_no_posts(client: TestClient) -> None:
+    """With the Phase 1 stub service, the home page shows 'No posts yet'.
+
+    This is the canonical empty-state marker; Phase 2 seeds a welcome
+    post so this test will need to be updated when the DB lands.
+    """
+    response = client.get("/")
+    assert response.status_code == 200
+    assert "No posts yet" in response.text
+
+
+def test_layout_includes_logo_image(client: TestClient) -> None:
+    """Shared layout references the generated logo asset paths.
+
+    We check for the stem (``/static/img/logo.``) rather than a specific
+    extension so both the <source srcset="...webp"> and <img src="...png">
+    markup are covered by a single assertion.
+    """
+    response = client.get("/")
+    assert response.status_code == 200
+    assert "/static/img/logo." in response.text
+
+
+def test_nav_marks_active_page(client: TestClient) -> None:
+    """The About page renders ``aria-current=\"page\"`` on its nav link.
+
+    Exercises the shared layout's active-nav logic end-to-end without
+    inspecting internals.
+    """
+    response = client.get("/about")
+    assert response.status_code == 200
+    # The pair should appear exactly once per active link; we only need
+    # to prove it's present at all.
+    assert 'aria-current="page"' in response.text