refactor: split tool declarations into domain files + role config UI

tools/__init__.py shrinks from 1,137 → 250 lines. Each domain file now
owns both its callables and its FunctionDeclarations (DECLARATIONS list),
so adding a new tool only touches one file.

New TOOL_CATEGORIES dict exported from __init__ — used by the UI for
grouped tool checkboxes.

Role config UI (Settings → Model Registry → Role Assignments):
- ⚙ button per role expands an inline configure panel
- Textarea for system_append (injected into system prompt for this role)
- Grouped checkboxes for tool allow-list (all checked = no restriction)
- POST /api/models/role-config saves both fields; updates ROLE_CONFIG_DATA
  in-page so re-open reflects current state without a page reload

Backend:
- model_registry.set_role_config() writes system_append + tools to registry
- TOOL_CATEGORIES exported from tools/__init__ for UI rendering
- TOOLS.md header updated: 30 → 39 tools (ae_journal_* and cortex_* additions)

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

cortex/tools/ae_tasks.py

@@ -16,6 +16,8 @@ import json
 import logging
 from pathlib import Path
 
+from google.genai import types
+
 logger = logging.getLogger(__name__)
 
 # Resolved at import time — agents_sync is always at ~/agents_sync on this machine.
@@ -98,3 +100,20 @@ def _read_bucket(bucket_dir: Path) -> list[dict]:
         except Exception as e:
             logger.warning("Failed to read task file %s: %s", path, e)
     return tasks
+
+
+DECLARATIONS = [
+    types.FunctionDeclaration(
+        name="ae_task_list",
+        description=(
+            "List tasks from the agents_sync Kanban board (todo and in-progress). "
+            "Use this when asked about current work, pending tasks, or project status."
+        ),
+        parameters=types.Schema(
+            type=types.Type.OBJECT,
+            properties={
+                "include_done": types.Schema(type=types.Type.BOOLEAN, description="If true, also include completed tasks (default false)"),
+            },
+        ),
+    ),
+]