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/routes/settings.py

@@ -25,18 +25,17 @@ async def update_settings_route():
     if not isinstance(data, dict):
         return jsonify({"error": "Expected a JSON object"}), 400
 
-    if "default_model" in data or "intent_model" in data:
+    if "default_model" in data:
         installed = await get_installed_models()
-        for key in ("default_model", "intent_model"):
-            if key in data and data[key]:
-                model = str(data[key])
-                if installed and model not in installed:
-                    return jsonify({"error": f"Model '{model}' is not installed"}), 400
+        if data["default_model"]:
+            model = str(data["default_model"])
+            if installed and model not in installed:
+                return jsonify({"error": f"Model '{model}' is not installed"}), 400
 
-    # Empty string for model keys means "reset to system default".
+    # Empty string for default_model means "reset to system default".
     # Delete the DB row so get_setting() falls back to Config defaults
     # rather than returning "" and breaking model resolution everywhere.
-    _MODEL_KEYS = frozenset({"default_model", "intent_model"})
+    _MODEL_KEYS = frozenset({"default_model"})
     to_save = {}
     for k, v in data.items():
         str_v = str(v)
@@ -59,7 +58,6 @@ async def get_models_route():
     return jsonify({
         "models": models,
         "default_chat_model": Config.OLLAMA_MODEL,
-        "default_intent_model": Config.OLLAMA_INTENT_MODEL,
     })