Improve live status overview

[rohita5l]

Summary

• replace the verbose status dump with consistent Rich panels for the provider and configured agents only
• fetch managed policy and model availability live using the saved CLI profile, with explicit cached fallbacks
• show effective models/defaults, tracing, MCP count, Skills MCP scope, and endpoint
• add a concise read-only ug skills list command

Validation

• env -u ENABLE_SMART_ROUTING_V2 uv run pytest tests/test_cli.py -q (367 passed)
• uv run ruff check src/ucode/cli.py tests/test_cli.py
• uv run ruff format --check src/ucode/cli.py tests/test_cli.py
• live uv run ug status against saved profile dbc-a5d4177a-49dc