refactor: rewrite tool_developer profile for MCP server development ...

Complete migration from old-style user tools (tools/*.py) to MCP servers.

Profile changes:
- Replace write_tool, delete_tool, test_tool with create_mcp_server,
  test_mcp_tool, mcp_status, reload_tools
- Update system_prompt.txt with 10-step MCP workflow
- Rewrite subagent_system_prompt.txt with canonical server format,
  absolute rules, smoke-test procedures
- Remove mcp_servers mapping from config (no longer bound to
  external servers)

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

Improve prompt resilience and project context use

Agent improvements: mandatory planning, tool cleanup, smart_edit fixes ...

- Planning now mandatory on first message of every session (force_plan)
- RESOURCES, COMMITMENTS, ATOMICITY fields added to planning phase 1
- Todo auto-injected at iteration 0 so model tracks steps immediately
- Execution trigger injected after plan to prevent model treating plan as response
- Split developer profile: tool_developer (Navi tools) vs developer (general code)
- Simplified persona.txt: trimmed redundant content now handled by mechanics
- AIHelper.ask(): 120s timeout via asyncio.wait_for to prevent smart_edit hangs
- filesystem._smart_edit(): atomic write via temp file + os.replace()
- Removed 5 junk user tools (game project artifacts, trivial utilities)
- Removed instagram tools (to be rewritten); cleaned enabled.json

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