v1.11.3: fix ctx_max capture via /props endpoint

- llama-server does not emit n_ctx in timings (confirmed empirically);
  dead code at inference.ts:479 and compaction.ts:300 never fired
- New model-context.ts: cached fetch of /upstream/<model>/props
  with positive-cache (no TTL) and 60s negative-cache
- Wired into all 4 ctx_max write sites: 3 in inference.ts
  (executeToolPhase, finalizeCompletion, runCapHitSummary) and
  1 in compaction.ts (summary row INSERT)
- AbortController 3s timeout, lenient parsing with sensible defaults
- 12 new vitest cases for the cache module (59 total)
- 7 historical assistant rows backfilled manually (see notes)

apps/server/src/index.ts

@@ -20,6 +20,7 @@ import { createInferenceRunner } from './services/inference.js';
 import { createBroker } from './services/broker.js';
 import { listSkills } from './services/skills.js';
 import * as compaction from './services/compaction.js';
+import { configureModelContext } from './services/model-context.js';
 
 async function main() {
   const config = loadConfig();
@@ -48,6 +49,11 @@ async function main() {
   await applySchema(sql);
   app.log.info('database schema applied');
 
+  // v1.11.3: tell the model-context cache where llama-swap lives. Cache
+  // lookups go to ${LLAMA_SWAP_URL}/upstream/<model>/props to read
+  // default_generation_settings.n_ctx — the value persisted as messages.ctx_max.
+  configureModelContext({ llamaSwapUrl: config.LLAMA_SWAP_URL });
+
   await app.register(fastifyWebsocket);
 
   app.get('/api/health', async () => {