feat(writing): M3 — one-shot prose generation via mana-llm

Server:
- New llmText() helper in apps/api/src/lib/llm.ts for plain-text
  (non-streaming) completions with token-usage reporting.
- POST /api/v1/writing/generations (Hono + requireTier('beta'))
  accepts system+user prompts, forwards to mana-llm (default model
  ollama/gemma3:4b), returns raw output + model + tokenUsage. The
  endpoint is stateless — draft/version bookkeeping is entirely
  client-side so the same route serves refinement calls later.

Client:
- writing/api.ts — Bearer-authed fetch client (follows the food/
  news-research pattern).
- writing/utils/prompt-builder.ts — pure builder turning a briefing
  (+ optional style preset / extracted principles) into a system+user
  pair. Forbids preamble / sign-off / meta commentary so the output is
  ready to paste into a version.
- writing/stores/generations.svelte.ts — orchestrates the full flow:
  queued → running → call → new LocalDraftVersion → pointer flip →
  succeeded. On failure leaves the current version untouched with the
  error on the generation record. Emits WritingDraftGenerationStarted /
  WritingDraftVersionCreated / WritingDraftGenerationFailed events.

UI:
- Generate button in DetailView.svelte (label flips "Generate" / "Neu
  generieren" based on whether the draft already has content).
- GenerationStatus.svelte strip surfaces queued / running / failed with
  model + duration badges; succeeded generations auto-disappear because
  the new version is already live via the currentVersionId pointer.

M3 is synchronous and non-streaming by design. M7 adds mission-based
long-form with streaming + outline stage + reference injection. M6 will
reuse the same /generations endpoint for selection-refinement prompts.

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

apps/api/src/index.ts

@@ -42,6 +42,7 @@ import { newsRoutes } from './modules/news/routes';
 import { newsResearchRoutes } from './modules/news-research/routes';
 import { articlesRoutes } from './modules/articles/routes';
 import { tracesRoutes } from './modules/traces/routes';
+import { writingRoutes } from './modules/writing/routes';
 import { presiRoutes } from './modules/presi/routes';
 import { researchRoutes } from './modules/research/routes';
 import { whoRoutes } from './modules/who/routes';
@@ -96,6 +97,7 @@ const RESOURCE_MODULES = [
 	'research',
 	'traces',
 	'who',
+	'writing',
 ] as const;
 for (const mod of RESOURCE_MODULES) {
 	app.use(`/api/v1/${mod}/*`, requireTier('beta'));
@@ -131,6 +133,7 @@ app.route('/api/v1/presi', presiRoutes);
 app.route('/api/v1/research', researchRoutes);
 app.route('/api/v1/website', websiteRoutes);
 app.route('/api/v1/who', whoRoutes);
+app.route('/api/v1/writing', writingRoutes);
 
 // ─── Server Info ────────────────────────────────────────────
 console.log(`mana-api starting on port ${PORT}...`);