feat: installable PWA with mobile share-target capture

- Corrected manifest (Jobbjakt branding, matching green theme, maskable
  icons, description/categories/scope/id).
- share_target (GET) maps a shared url/link into the same /?add= capture
  flow the bookmarklet uses, so mobile 'Share -> Jobbjakt' pre-fills Add
  Job.
- resolveCaptureUrl helper (tested) extracts the link from add or from a
  link embedded in shared text; App uses it and strips the params.
- Deliberately no offline service worker: the app deploys frequently and
  an aggressive cache would risk stale builds (documented in README).
- 4 unit tests; build compiles.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

job-tracker-ui/src/App.tsx

@@ -32,6 +32,7 @@ import ForgotPasswordPage from "./pages/ForgotPasswordPage";
 import ResetPasswordPage from "./pages/ResetPasswordPage";
 import RouteErrorPage from "./pages/RouteErrorPage";
 import { api } from "./api";
+import { resolveCaptureUrl } from "./captureUrl";
 import { clearAuthClientState, setAuthUserKey } from "./auth";
 import AppShell, { NavItem } from "./layout/AppShell";
 import { clearAccentColor, getAccentColor, getThemeModePref, setAccentColor, setThemeModePref, ThemeModePref } from "./themePrefs";
@@ -126,14 +127,16 @@ function Shell({ jobPageSize, setJobPageSize, jobColumns, setJobColumns, themeMo
     api.get<AuthConfig>("/auth/config").then((r) => setRequireAuth(Boolean(r.data?.requireAuth))).catch(() => setRequireAuth(false));
   }, []);
 
-  // Quick-capture bookmarklet target: /?add=<encoded job url> opens Add Job pre-filled.
+  // Quick-capture target: bookmarklet (/?add=<url>) or PWA share (url in `add`, or a link
+  // embedded in shared `addtext`). Opens Add Job pre-filled and strips the params.
   useEffect(() => {
-    const params = new URLSearchParams(location.search);
-    const add = params.get("add");
-    if (!add) return;
-    setCaptureUrl(add);
+    const url = resolveCaptureUrl(location.search);
+    if (!url) return;
+    setCaptureUrl(url);
     setAddOpen(true);
+    const params = new URLSearchParams(location.search);
     params.delete("add");
+    params.delete("addtext");
     navigate({ pathname: location.pathname, search: params.toString() }, { replace: true });
   }, [location.search, location.pathname, navigate]);
   useEffect(() => {