feat(llm-aliases): M5 — migrate consumers to MANA_LLM aliases

Final milestone of docs/plans/llm-fallback-aliases.md. Every backend
caller now requests models via the `mana/<class>` alias system instead
of hardcoded `ollama/...` strings. mana-llm resolves aliases through
`services/mana-llm/aliases.yaml` with health-aware fallback (M3) and
emits resolved-model + fallback metrics (M4).

SSOT moved to `packages/shared-ai/src/llm-aliases.ts` so apps/api,
apps/mana/apps/web, and services/mana-ai all import the same
`MANA_LLM` constant via the existing `@mana/shared-ai` workspace
dependency. Three additional sites (memoro-server, mana-events,
mana-research) inline the alias string with a SSOT comment because
they don't pull @mana/shared-ai today.

Migrated 14 sites across 10 files:
- apps/api: writing(LONG_FORM), comic(STRUCTURED), context(FAST_TEXT),
  food(VISION), plants(VISION), research orchestrator (3 tiers
  collapsed to STRUCTURED+FAST_TEXT/LONG_FORM)
- apps/mana/apps/web: voice/parse-task + parse-habit (STRUCTURED)
- services/mana-ai: planner llm-client + tick.ts (REASONING)
- services/mana-events: website-extractor (STRUCTURED, inlined)
- services/mana-research: mana-llm client (FAST_TEXT, inlined)
- apps/memoro/apps/server: ai.ts (FAST_TEXT, inlined)

Legacy env-vars removed: WRITING_MODEL, COMIC_STORYBOARD_MODEL,
VISION_MODEL, MANA_LLM_DEFAULT_MODEL. The chain in aliases.yaml is
now the single tuning surface; SIGHUP reloads it without redeploys.

New `scripts/validate-llm-strings.mjs` regex-scans 2538 files for
hardcoded `<provider>/<model>` strings and fails the build if any
land outside the SSOT or the explicitly-allowed paths (image-gen
modules, model-inspector code, this validator itself, the registry).
Wired into `validate:all` next to the i18n + theme validators.

Verified: `pnpm validate:llm-strings` clean, `pnpm --filter @mana/api
type-check` clean, `pnpm --filter @mana/ai-service type-check`
clean. Web type-check has 2 pre-existing errors in
SettingsSidebar.svelte (i18n MessageFormatter type drift, last
touched in 988c17a67 — unrelated to this work).

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

services/mana-ai/src/cron/tick.ts

@@ -30,6 +30,7 @@ import { loadActiveAgents, refreshAgentSnapshots, type ServerAgent } from '../db
 import { appendServerIteration, planToIteration } from '../db/iteration-writer';
 import { refreshSnapshots } from '../db/snapshot-refresh';
 import { createServerLlmClient, ProviderCallError } from '../planner/llm-client';
+import { MANA_LLM } from '@mana/shared-ai';
 import { SERVER_TOOLS } from '../planner/tools';
 import {
 	ticksTotal,
@@ -393,7 +394,7 @@ async function planOneMission(
 		pretickUsage24h,
 	});
 
-	const plannerModel = 'google/gemini-2.5-flash';
+	const plannerModel = MANA_LLM.REASONING;
 
 	// Claude-Code wU2 pattern: fold the middle of messages into a structured
 	// summary once cumulative tokens cross 92% of maxContextTokens.
@@ -493,7 +494,7 @@ async function planOneMission(
 	} catch (err) {
 		const msg = err instanceof Error ? err.message : String(err);
 		if (err instanceof ProviderCallError) {
-			const provider = inferProviderFromModel('google/gemini-2.5-flash');
+			const provider = inferProviderFromModel(MANA_LLM.REASONING);
 			providerErrorsTotal.inc({ provider, kind: err.kind });
 		}
 		console.warn(`[mana-ai tick] mission=${m.id} planner loop failed: ${msg}`);

services/mana-ai/src/planner/llm-client.ts

@@ -15,6 +15,7 @@ import type {
 	LlmFinishReason,
 	ToolCallRequest,
 } from '@mana/shared-ai';
+import { MANA_LLM } from '@mana/shared-ai';
 
 /** Thrown when mana-llm returns a non-2xx status. ``kind`` mirrors the
  *  structured ProviderError vocabulary (blocked / truncated / auth /
@@ -37,7 +38,7 @@ export interface ServerLlmClientOptions {
 	readonly fetchTimeoutMs?: number;
 }
 
-const DEFAULT_MODEL = 'google/gemini-2.5-flash';
+const DEFAULT_MODEL = MANA_LLM.REASONING;
 const DEFAULT_FETCH_TIMEOUT_MS = 120_000;
 
 export function createServerLlmClient(opts: ServerLlmClientOptions): LlmClient {

services/mana-events/src/discovery/website-extractor.ts

@@ -121,7 +121,10 @@ async function llmExtractEvents(
 			method: 'POST',
 			headers: { 'Content-Type': 'application/json' },
 			body: JSON.stringify({
-				model: 'ollama/gemma3:4b',
+				// JSON event extraction → STRUCTURED alias (resolved by mana-llm).
+				// SSOT: packages/shared-ai/src/llm-aliases.ts. Inlined because
+				// mana-events doesn't depend on @mana/shared-ai today.
+				model: 'mana/structured',
 				messages: [
 					{ role: 'system', content: buildExtractionPrompt() },
 					{ role: 'user', content: `Extrahiere Events von dieser Seite:\n\n${pageContent}` },

services/mana-research/src/clients/mana-llm.ts

@@ -19,7 +19,11 @@ export class ManaLlmClient {
 			method: 'POST',
 			headers: { 'Content-Type': 'application/json' },
 			body: JSON.stringify({
-				model: opts.model ?? 'ollama/gemma3:4b',
+				// Default to the FAST_TEXT alias — mana-research uses mana-llm
+				// for query classification and short-form analysis. SSOT:
+				// packages/shared-ai/src/llm-aliases.ts. Inlined because
+				// mana-research doesn't depend on @mana/shared-ai today.
+				model: opts.model ?? 'mana/fast-text',
 				messages,
 				max_tokens: opts.maxTokens ?? 256,
 				temperature: opts.temperature ?? 0.2,