Remove curated models table, use live provider APIs with filtering

- Remove harness_curated_models table from schema
- Remove /api/models/curated route and all curated model functions
- Move KNOWN_MODELS pricing table to model-providers.ts and enrich
  live API results with pricing/context window data
- Filter out old models: dated IDs (claude-3-opus-20240229), legacy
  families (claude-3-*, gpt-3.5-*, gpt-4-*, text-*, etc.)
- Update model_list chat tool to use fetchAllModels() instead of DB
- Update ModelsTab to fetch from /api/models, remove toggle/delete
- Update getUsageSummary to use KNOWN_MODELS for cost lookup
- Simplify boot.ts: remove model syncing, keep agent auto-discovery

packages/db/drizzle/meta/_journal.json

@@ -29,6 +29,13 @@
       "when": 1774179559510,
       "tag": "0003_damp_glorian",
       "breakpoints": true
+    },
+    {
+      "idx": 4,
+      "version": "7",
+      "when": 1774180634616,
+      "tag": "0004_complete_jack_murdock",
+      "breakpoints": true
     }
   ]
 }