feat: public platform, admin console, templates, landing docs

Projects become publicly browsable after admin approval; management and
secret-adjacent reads (logs, variables, exec, connection URLs) require
owner/member/admin auth, and platform controls sit behind RequireAdmin.

- Backend: OptionalAuth middleware, read/authed/admin route groups,
  projects.is_approved + service_templates.owner_id migration,
  visibility-aware sqlc queries, admin overview/users/approval endpoints,
  EnsureAdminAccount bootstrap (ADMIN_* env), 30 seeded templates with
  owner CRUD, managed-database connection URLs gated owner+admin, fix
  DB.Stats() infinite recursion.
- Frontend: expandable persisted sidebar + clickable user menu, public
  landing page with searchable docs browser (GitHub sync, bundled
  snapshot + localStorage fallback), DocsBrowser shared with /docs,
  template create/edit/JSON-upload for owned templates, database create
  dialog, admin console (stats, approvals, project edit/delete, user
  admin toggles), HA/Security/Usage polish with dead CSS tokens mapped
  to real theme vars, anonymous-safe gating on every mutation control.
- Tests: safe window.localStorage access fixes happy-dom crashes in
  PlatformShell and canvas storage.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

app/frontend/src/index.css

@@ -1582,3 +1582,106 @@ textarea {
 .v-tick .sig.r { background: var(--error); }
 
 /* Rail active indicator handled via .nav-item.active::before */
+
+/* Rendered documentation */
+.docs-article {
+  color: var(--text-secondary);
+  font-size: 13.5px;
+  line-height: 1.7;
+  max-width: 72ch;
+}
+.docs-article h1 {
+  color: var(--text-primary);
+  font-size: 22px;
+  font-weight: 700;
+  letter-spacing: -0.02em;
+  margin: 0 0 14px;
+}
+.docs-article h2 {
+  color: var(--text-primary);
+  font-size: 16.5px;
+  font-weight: 650;
+  margin: 26px 0 10px;
+  padding-top: 14px;
+  border-top: 1px solid var(--border-subtle);
+}
+.docs-article h3 {
+  color: var(--text-primary);
+  font-size: 14px;
+  font-weight: 600;
+  margin: 20px 0 8px;
+}
+.docs-article h4 {
+  color: var(--text-primary);
+  font-size: 13px;
+  font-weight: 600;
+  margin: 16px 0 6px;
+}
+.docs-article p { margin: 10px 0; }
+.docs-article a {
+  color: var(--accent-primary);
+  text-decoration: none;
+  border-bottom: 1px solid var(--accent-primary-glow);
+}
+.docs-article a:hover { border-bottom-color: var(--accent-primary); }
+.docs-article ul, .docs-article ol {
+  margin: 10px 0;
+  padding-left: 22px;
+}
+.docs-article ul { list-style: disc; }
+.docs-article ol { list-style: decimal; }
+.docs-article li { margin: 4px 0; }
+.docs-article li::marker { color: var(--text-tertiary); }
+.docs-article code {
+  font-family: 'JetBrains Mono', monospace;
+  font-size: 12px;
+  background: var(--surface-muted);
+  border: 1px solid var(--border-subtle);
+  border-radius: 5px;
+  padding: 1.5px 5px;
+  color: var(--accent-secondary);
+}
+.docs-article pre {
+  background: var(--bg-void);
+  border: 1px solid var(--border-subtle);
+  border-radius: var(--radius-md);
+  padding: 14px 16px;
+  margin: 14px 0;
+  overflow-x: auto;
+}
+.docs-article pre code {
+  background: none;
+  border: none;
+  padding: 0;
+  font-size: 12px;
+  color: var(--text-secondary);
+}
+.docs-article blockquote {
+  border-left: 3px solid var(--accent-primary);
+  padding: 2px 0 2px 14px;
+  margin: 14px 0;
+  color: var(--text-tertiary);
+}
+.docs-article table {
+  width: 100%;
+  border-collapse: collapse;
+  margin: 14px 0;
+  font-size: 12.5px;
+}
+.docs-article th {
+  text-align: left;
+  font-weight: 600;
+  color: var(--text-primary);
+  padding: 8px 12px;
+  border-bottom: 1px solid var(--border-default);
+}
+.docs-article td {
+  padding: 8px 12px;
+  border-bottom: 1px solid var(--border-subtle);
+}
+.docs-article hr {
+  border: none;
+  border-top: 1px solid var(--border-subtle);
+  margin: 24px 0;
+}
+.docs-article img { max-width: 100%; border-radius: var(--radius-md); }