feat(journal): LLM tools (record_moment, search_journal) + system prompt wiring

- services/tools/journal.py — record_moment + search_journal tool handlers
- services/tools/_registry.py: add `journal` flag on ToolDef + tool() decorator
- get_tools_for_user(user_id, conversation_type='chat'|'journal') —
  exclude journal-only tools from chat sessions; exclude set_rag_scope
  from journal sessions
- services/tools/__init__.py: register the new journal module; drop the
  unused get_briefing_tools export
- services/llm.py build_context: short-circuit for journal conversations,
  using journal_pipeline.build_journal_system_prompt and skipping all
  notes-RAG injection (preserves the journal/notes isolation invariant)
- services/generation_task.py: pass conversation_type into get_tools_for_user

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/fabledassistant/services/tools/_registry.py

@@ -27,6 +27,7 @@ class ToolDef:
     handler: ToolHandler
     read_only: bool = False
     briefing: bool = False
+    journal: bool = False
     requires: str | None = None
     required_params: list[str] = field(default_factory=list)
 
@@ -57,6 +58,7 @@ def tool(
     required: list[str] | None = None,
     read_only: bool = False,
     briefing: bool = False,
+    journal: bool = False,
     requires: str | None = None,
 ) -> Callable[[ToolHandler], ToolHandler]:
     """Register an async tool handler with its schema metadata."""
@@ -71,6 +73,7 @@ def tool(
             handler=fn,
             read_only=read_only,
             briefing=briefing,
+            journal=journal,
             requires=requires,
             required_params=required or [],
         )
@@ -90,27 +93,29 @@ async def _check_requires(user_id: int, requires: str) -> bool:
     return True
 
 
-async def get_tools_for_user(user_id: int) -> list[dict]:
-    """Build the tool schema list for a user based on configured integrations."""
+async def get_tools_for_user(
+    user_id: int, *, conversation_type: str = "chat"
+) -> list[dict]:
+    """Build the tool schema list for a user, scoped by conversation type.
+
+    - 'chat': all tools except those marked journal-only.
+    - 'journal': all tools except set_rag_scope (scope is implicit in journal).
+    """
     tools: list[dict] = []
     for td in _REGISTRY.values():
         if td.requires and not await _check_requires(user_id, td.requires):
             continue
+        if conversation_type == "journal":
+            if td.name == "set_rag_scope":
+                continue
+        else:
+            if td.journal:
+                continue
         tools.append(td.schema())
-    logger.debug("User %d: %d tools available", user_id, len(tools))
-    return tools
-
-
-async def get_briefing_tools(user_id: int) -> list[dict]:
-    """Return only the tool schemas marked ``briefing=True``."""
-    all_tools = await get_tools_for_user(user_id)
-    names = {td.name for td in _REGISTRY.values() if td.briefing}
-    filtered = [t for t in all_tools if t["function"]["name"] in names]
     logger.debug(
-        "Briefing tools for user %d: %d of %d selected",
-        user_id, len(filtered), len(all_tools),
+        "User %d / %s: %d tools available", user_id, conversation_type, len(tools)
     )
-    return filtered
+    return tools
 
 
 async def execute_tool(