feat(assistant): add multi-dialog UX, task-aware llm settings, and i18n cleanup

backend/src/services/llm_prompt_templates.py

@@ -61,23 +61,109 @@ DEFAULT_LLM_PROMPTS: Dict[str, str] = {
 # [/DEF:DEFAULT_LLM_PROMPTS:Constant]
 
 
+# [DEF:DEFAULT_LLM_PROVIDER_BINDINGS:Constant]
+# @TIER: STANDARD
+# @PURPOSE: Default provider binding per task domain.
+DEFAULT_LLM_PROVIDER_BINDINGS: Dict[str, str] = {
+    "dashboard_validation": "",
+    "documentation": "",
+    "git_commit": "",
+}
+# [/DEF:DEFAULT_LLM_PROVIDER_BINDINGS:Constant]
+
+
+# [DEF:DEFAULT_LLM_ASSISTANT_SETTINGS:Constant]
+# @TIER: STANDARD
+# @PURPOSE: Default planner settings for assistant chat intent model/provider resolution.
+DEFAULT_LLM_ASSISTANT_SETTINGS: Dict[str, str] = {
+    "assistant_planner_provider": "",
+    "assistant_planner_model": "",
+}
+# [/DEF:DEFAULT_LLM_ASSISTANT_SETTINGS:Constant]
+
+
 # [DEF:normalize_llm_settings:Function]
 # @TIER: STANDARD
 # @PURPOSE: Ensure llm settings contain stable schema with prompts section and default templates.
 # @PRE: llm_settings is dictionary-like value or None.
 # @POST: Returned dict contains prompts with all required template keys.
 def normalize_llm_settings(llm_settings: Any) -> Dict[str, Any]:
-    normalized: Dict[str, Any] = {"providers": [], "default_provider": "", "prompts": {}}
+    normalized: Dict[str, Any] = {
+        "providers": [],
+        "default_provider": "",
+        "prompts": {},
+        "provider_bindings": {},
+        **DEFAULT_LLM_ASSISTANT_SETTINGS,
+    }
     if isinstance(llm_settings, dict):
-        normalized.update({k: v for k, v in llm_settings.items() if k in ("providers", "default_provider", "prompts")})
+        normalized.update(
+            {
+                k: v
+                for k, v in llm_settings.items()
+                if k
+                in (
+                    "providers",
+                    "default_provider",
+                    "prompts",
+                    "provider_bindings",
+                    "assistant_planner_provider",
+                    "assistant_planner_model",
+                )
+            }
+        )
     prompts = normalized.get("prompts") if isinstance(normalized.get("prompts"), dict) else {}
     merged_prompts = deepcopy(DEFAULT_LLM_PROMPTS)
     merged_prompts.update({k: v for k, v in prompts.items() if isinstance(v, str) and v.strip()})
     normalized["prompts"] = merged_prompts
+    bindings = normalized.get("provider_bindings") if isinstance(normalized.get("provider_bindings"), dict) else {}
+    merged_bindings = deepcopy(DEFAULT_LLM_PROVIDER_BINDINGS)
+    merged_bindings.update({k: v for k, v in bindings.items() if isinstance(v, str)})
+    normalized["provider_bindings"] = merged_bindings
+    for key, default_value in DEFAULT_LLM_ASSISTANT_SETTINGS.items():
+        value = normalized.get(key, default_value)
+        normalized[key] = value.strip() if isinstance(value, str) else default_value
     return normalized
 # [/DEF:normalize_llm_settings:Function]
 
 
+# [DEF:is_multimodal_model:Function]
+# @TIER: STANDARD
+# @PURPOSE: Heuristically determine whether model supports image input required for dashboard validation.
+# @PRE: model_name may be empty or mixed-case.
+# @POST: Returns True when model likely supports multimodal input.
+def is_multimodal_model(model_name: str) -> bool:
+    token = (model_name or "").strip().lower()
+    if not token:
+        return False
+    multimodal_markers = (
+        "gpt-4o",
+        "gpt-4.1",
+        "vision",
+        "vl",
+        "gemini",
+        "claude-3",
+        "claude-sonnet-4",
+    )
+    return any(marker in token for marker in multimodal_markers)
+# [/DEF:is_multimodal_model:Function]
+
+
+# [DEF:resolve_bound_provider_id:Function]
+# @TIER: STANDARD
+# @PURPOSE: Resolve provider id configured for a task binding with fallback to default provider.
+# @PRE: llm_settings is normalized or raw dict from config.
+# @POST: Returns configured provider id or fallback id/empty string when not defined.
+def resolve_bound_provider_id(llm_settings: Any, task_key: str) -> str:
+    normalized = normalize_llm_settings(llm_settings)
+    bindings = normalized.get("provider_bindings", {})
+    bound = bindings.get(task_key)
+    if isinstance(bound, str) and bound.strip():
+        return bound.strip()
+    default_provider = normalized.get("default_provider", "")
+    return default_provider.strip() if isinstance(default_provider, str) else ""
+# [/DEF:resolve_bound_provider_id:Function]
+
+
 # [DEF:render_prompt:Function]
 # @TIER: STANDARD
 # @PURPOSE: Render prompt template using deterministic placeholder replacement with graceful fallback.