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>

apps/api/src/modules/food/routes.ts

@@ -30,14 +30,13 @@ import {
 	type MealAnalysis,
 } from '@mana/shared-types';
 import { logger, type AuthVariables } from '@mana/shared-hono';
+import { MANA_LLM } from '@mana/shared-ai';
 
 const LLM_URL = process.env.MANA_LLM_URL || 'http://localhost:3025';
-// mana-llm parses model strings as `provider/model` (router.py:_parse_model).
-// Default to Gemma 3 (4B, multimodal) on the local Ollama instance — it
-// runs on the GPU server (192.168.178.11) via the gpu-proxy bridge and
-// supports vision out of the box. Override with VISION_MODEL=google/gemini-2.0-flash
-// (or similar) once mana-llm has GOOGLE_API_KEY configured.
-const VISION_MODEL = process.env.VISION_MODEL || 'ollama/gemma3:4b';
+// mana-llm resolves this alias to a healthy vision model (chain in
+// services/mana-llm/aliases.yaml). To swap the chain, edit the YAML
+// and SIGHUP — no service redeploy here.
+const VISION_MODEL = MANA_LLM.VISION;
 
 const llm = createOpenAICompatible({
 	name: 'mana-llm',