feat: implement interactive smart restore negotiation

[JacksonFergusonDev]

Description

This PR addresses the "Smart Restore" item from the Phase 1 roadmap. Previously, running git pulsar restore on a dirty file would trigger a hard exit to protect uncommitted changes, forcing the user to blindly append --force.

This updates the behavior to use an interactive state machine, giving the user the ability to safely inspect the delta before deciding to overwrite or cancel.

Changes

• Git Abstraction (git_wrapper.py): Expanded run_diff to accept an optional file argument, properly isolating the path with -- to prevent refspec collisions.
• Business Logic (ops.py): Replaced the sys.exit(1) kill-switch in restore_file with a rich.prompt.Prompt loop ([O]verwrite / [V]iew Diff / [C]ancel).
• Testing (test_ops.py, test_git_wrapper.py):
  • Removed the obsolete test_restore_dirty_fails.
  • Added granular mock coverage for all three interactive branches (test_restore_dirty_cancels, test_restore_dirty_overwrites, test_restore_dirty_views_diff).
  • Added regression coverage for file-targeted diff construction.
• Documentation: Updated architecture mappings, test strategy docs, and checked off the roadmap item.

Verification

• Tested interactive pager mapping (diffs open in less and return cleanly to the prompt).
• Verified pytest suite passes with new mocked Prompt sequences.