Remove intent model entirely; quick-capture uses primary model

The separate intent model (OLLAMA_INTENT_MODEL / qwen2.5:7b) is removed
from every part of the system. All classification now uses the primary model.

Changes:
- config.py: remove OLLAMA_INTENT_MODEL
- intent.py: remove classify_intent() and all supporting infrastructure
  (_SYSTEM_PROMPT_TEMPLATE, _RESEARCH_PREFIX, _PRIOR_WORK_REFS); file now
  only contains the quick-capture classifier
- quick_capture.py: classify_capture_intent() now called with Config.OLLAMA_MODEL
- generation_task.py: remove intent_model_setting DB lookup and get_setting import;
  history summarization and research pipeline use the primary model directly
- research.py: remove intent_model parameter from run_research_pipeline() and
  _generate_sub_queries(); both use the model param throughout
- routes/settings.py: remove intent_model from model-key validation and response
- app.py: remove intent model pre-warming at startup
- SettingsView.vue: remove Intent Model selector and related refs/state

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/fabledassistant/app.py

@@ -131,15 +131,9 @@ def create_app() -> Quart:
                 except Exception:
                     logger.warning("Failed to warm model '%s'", model, exc_info=True)
 
-        # Pull main model and (if configured) a separate intent model concurrently,
-        # then warm them into VRAM so the first user request doesn't cold-load both
-        # simultaneously (which causes Ollama 500 races).
-        # Fire-and-forget so pulls/warming don't block startup.
+        # Pull and warm the main model into VRAM at startup so the first request is fast.
+        asyncio.create_task(_pull_model(Config.OLLAMA_MODEL, warm=True))
         models_to_warm = {Config.OLLAMA_MODEL}
-        if Config.OLLAMA_INTENT_MODEL and Config.OLLAMA_INTENT_MODEL != Config.OLLAMA_MODEL:
-            models_to_warm.add(Config.OLLAMA_INTENT_MODEL)
-        for _model in models_to_warm:
-            asyncio.create_task(_pull_model(_model, warm=True))
         # Also pull the embedding model (nomic-embed-text by default), but no need to warm it.
         if Config.EMBEDDING_MODEL not in models_to_warm:
             asyncio.create_task(_pull_model(Config.EMBEDDING_MODEL, warm=False))