Add profile_id support to list_tools ...

ListToolsTool now accepts an optional `profile_id` parameter. When
provided, it returns only the tools enabled for that specific profile
(enabled_tools + user tools + resolved MCP tools). This helps the agent
preview what a profile can do before switching.

- Updated ListToolsTool.execute() with profile-aware filtering
- Patched _profile_registry in build_default_registries
- Patched _mcp_manager in main.py startup loop

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

Add self-extension tool system: write_tool, list_tools, tool_manual ...

- loader.py: module-level format (name/description/parameters/execute)
  preferred, class-based as fallback; isolated errors per file
- write_tool: validates + writes tools/name.py, reloads registry,
  adds to tools/enabled.json in one call
- list_tools: live tool list from registry (prevents hallucination)
- tool_manual: serves manuals/*.md or auto-generates from schema
- reload_tools: hot-reload without server restart
- registry: registry injection pattern for tools that need it;
  _builtin_names set to guard against reload overwriting builtins

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