Phase 8: CSV + ICS export, print view, MkDocs docs, SBOM + dev-mode auth

Auth (Test-Mode):
  - middleware.AuthMiddleware now takes a devMode flag. In dev,
    requests without Authorization fall back to a deterministic dev
    UUID (00000000-...-001) and role=teacher. ENVIRONMENT=production
    re-enables the strict 401 path.
  - main.go wires devMode = cfg.Environment != "production".
  - page.tsx replaces the red 'Anmeldung noch nicht integriert' banner
    with a softer Testumgebung notice; the manual-token form moves
    behind a nested details block.

Export endpoints (school-service):
  - LoadExportLessons joins tt_lesson with tt_period for wall-clock
    times; one query feeds both CSV and ICS.
  - WriteCSV streams 10 columns including pinned flag.
  - WriteICS emits one VEVENT per lesson anchored to a Monday — caller
    overridable via ?start=YYYY-MM-DD. RFC 5545 escapes for ',', ';',
    '\n' in icsEscape().
  - NextMonday helper for the default anchor.
  - GET /timetable/solutions/:id/export.{csv,ics} handlers attach
    Content-Disposition: attachment so browsers download instead of
    rendering.

Frontend:
  - lib/stundenplan/api.ts downloadSolutionExport() fetches as blob,
    triggers a synthetic <a download> click, and forwards the JWT when
    present.
  - PlanView gains CSV / ICS / Drucken buttons next to the perspective
    selector. The toolbar carries class 'no-print' so window.print()
    yields only the grid.
  - globals.css @media print rule hides chrome, forces white
    background, gives the table proper borders for A4.

Docs:
  - docs-src/services/stundenplan/{index,architecture,constraints,
    solver-tuning,export}.md with nav entry in mkdocs.yml under
    Services → Stundenplaner.
  - sbom/stundenplan/README.md lists manually-verified key dependencies
    and the policy reference. scripts/stundenplan-sbom.sh generates
    full machine-readable inventories via go-licenses + pip-licenses
    + license-checker when those tools are available.

Tests:
  - internal/services/timetable_exports_test.go: 4 unit tests covering
    CSV column layout + quoting, ICS structure + DTSTART formatting,
    icsEscape special chars, NextMonday weekday math.
  - studio-v2/e2e/stundenplan-export.spec.ts split out of the main spec
    file (LOC budget) — 3 tests for button render, CSV download,
    ICS download.
  - mockSchoolApi extended with export.csv + export.ics routes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

studio-v2/app/stundenplan/page.tsx

@@ -76,48 +76,47 @@ export default function StundenplanPage() {
           <HelpPanel />
 
           <div
-            className={`mb-4 p-3 rounded-xl border backdrop-blur-xl ${
-              isDark ? 'bg-amber-500/10 border-amber-500/30 text-amber-200' : 'bg-amber-50 border-amber-200 text-amber-900'
+            className={`mb-4 p-3 rounded-xl border backdrop-blur-xl text-sm ${
+              isDark ? 'bg-emerald-500/10 border-emerald-500/30 text-emerald-200' : 'bg-emerald-50 border-emerald-200 text-emerald-900'
             }`}
           >
             <details>
-              <summary className="cursor-pointer text-sm font-medium">
-                Anmeldung noch nicht integriert — Dev-Token setzen
+              <summary className="cursor-pointer font-medium">
+                Testumgebung — Anmeldung deaktiviert
               </summary>
-              <div className="mt-3 space-y-2 text-sm">
+              <div className="mt-2 space-y-2">
                 <p>
-                  Bis die volle BreakPilot-Anmeldung an dieses Modul angebunden ist, muss
-                  ein gueltiger JWT-Token manuell hinterlegt werden. Ohne Token antwortet
-                  die API mit <code className={`px-1 rounded ${isDark ? 'bg-white/10' : 'bg-amber-100'}`}>Authorization header required</code>.
+                  Der school-service laeuft im Development-Mode und akzeptiert Requests
+                  ohne JWT. Alle Aktionen werden einem festen Dev-User
+                  zugeordnet (<code className={`px-1 rounded ${isDark ? 'bg-white/10' : 'bg-emerald-100'}`}>00000000-0000-0000-0000-000000000001</code>).
                 </p>
-                <ol className="list-decimal list-inside space-y-1 opacity-90">
-                  <li>An BreakPilot anmelden (z.B. ueber das Lehrer-Login)</li>
-                  <li>Im Browser DevTools → Application/Storage → Cookies oder localStorage den
-                      JWT-Token kopieren (Feldname kann je nach Login-Flow variieren)</li>
-                  <li>Token unten einfuegen, Speichern, Seite neu laden</li>
-                </ol>
-                <div className="mt-2 flex gap-2">
-                  <input
-                    type="password"
-                    value={token}
-                    onChange={e => setToken(e.target.value)}
-                    placeholder="Bearer-Token (ohne 'Bearer '-Prefix)"
-                    className={`flex-1 px-3 py-1.5 rounded-lg text-sm ${
-                      isDark ? 'bg-white/10 border border-white/20 text-white' : 'bg-white border border-slate-300 text-slate-900'
-                    }`}
-                  />
-                  <button
-                    onClick={handleSaveToken}
-                    className="px-3 py-1.5 rounded-lg bg-amber-500 hover:bg-amber-600 text-white text-sm font-medium"
-                  >
-                    Speichern
-                  </button>
-                </div>
-                {tokenSaved && (
-                  <p className={`text-xs ${isDark ? 'text-emerald-300' : 'text-emerald-700'}`}>
-                    Token gespeichert. Seite neu laden, um die Aenderung zu uebernehmen.
-                  </p>
-                )}
+                <p>
+                  Fuer Production muss <code className={`px-1 rounded ${isDark ? 'bg-white/10' : 'bg-emerald-100'}`}>ENVIRONMENT=production</code> gesetzt werden — dann ist ein gueltiger
+                  JWT in jedem Request Pflicht.
+                </p>
+                <details className="opacity-70">
+                  <summary className="cursor-pointer text-xs">Manueller Token (falls noetig)</summary>
+                  <div className="mt-2 flex gap-2">
+                    <input
+                      type="password"
+                      value={token}
+                      onChange={e => setToken(e.target.value)}
+                      placeholder="Bearer-Token (optional)"
+                      className={`flex-1 px-3 py-1.5 rounded-lg text-sm ${
+                        isDark ? 'bg-white/10 border border-white/20 text-white' : 'bg-white border border-slate-300 text-slate-900'
+                      }`}
+                    />
+                    <button
+                      onClick={handleSaveToken}
+                      className="px-3 py-1.5 rounded-lg bg-emerald-500 hover:bg-emerald-600 text-white text-sm font-medium"
+                    >
+                      Speichern
+                    </button>
+                  </div>
+                  {tokenSaved && (
+                    <p className="mt-1 text-xs opacity-90">Token gespeichert. Seite neu laden.</p>
+                  )}
+                </details>
               </div>
             </details>
           </div>