fix(agent): resolve graph compilation and cli bugs from review

[Jaydeep869]

Summary

This PR addresses the remaining review feedback, bugs, and CI failures for PR kusari-oss#137 on the main repository. Merging this into your feature/langgraph-agent branch will automatically update PR kusari-oss#137 and resolve the failing checks.

Fixes included:

• Bug 1 (cli.py): Fixed the UnboundLocalError in cmd_run() by ensuring final_state is handled and adding an early return if the agent graph layout fails.
• Merge Artifact (cli.py): Restored the cmd_profiles function that was lost during a recent merge with main, which was causing uv run darnit --help and several tests to crash with a NameError.
• Lazy Import (graph.py): Moved langgraph imports (StateGraph, END) entirely inside build_graph() to fix the ModuleNotFoundError during pytest collection.
• Test Integrity: Updated the MCP server integration test to check len(tools) >= 15 to account for new commands merged from main.
• Linting: Removed unused imports to ensure the ruff CI check passes.

Type of Change

• Bug fix (non-breaking change fixing an issue)
• New feature (non-breaking change adding functionality)
• Breaking change (fix or feature causing existing functionality to change)
• Documentation update
• Refactoring (no functional changes)

Framework Changes Checklist

If this PR modifies the darnit framework (packages/darnit/):

• Updated framework spec (openspec/specs/framework-design/spec.md) if behavior changed
• Ran uv run python scripts/validate_sync.py --verbose and it passes
• Ran uv run python scripts/generate_docs.py and committed any doc changes

Control/TOML Changes Checklist

If this PR modifies controls or TOML configuration:

• Control metadata defined in TOML (not Python code)
• SARIF fields (description, severity, help_url) included where appropriate
• Ran validation to confirm TOML schema compliance

Testing

• Tests pass locally (uv run pytest tests/ -v)
• Added tests for new functionality (if applicable)
• Linting passes (uv run ruff check .)

Additional Notes

Tested locally and the full suite passes!