Fix immediate stats after editor agent commits

[Siddhant-K-code]

Summary

• Add a best-effort daemon family sync before git-ai stats and git-ai status read attribution data
• Add delayed daemon-side regression coverage for Cursor and VS Code Copilot editor-like commit flows
• Add coverage that pasted/copied code without an agent hook remains untracked rather than AI-attributed

Fixes #1423.
Refs #1584.

Validation

Run from the repo root on this branch:

task fmt
task lint
task test TEST_FILTER=test_cursor_editor_commit_immediate_stats_waits_for_daemon_note
task test TEST_FILTER=test_copilot_vscode_commit_immediate_stats_waits_for_daemon_note
task test TEST_FILTER=test_copied_code_without_agent_hook_remains_untracked_after_immediate_stats

Expected outcomes:

• task fmt exits cleanly with no rustfmt diffs.
• task lint exits cleanly with no clippy/lint failures.
• Cursor immediate-stats regression passes: git-ai status --json and immediate git-ai stats HEAD --json report ai_additions == 1 after the delayed daemon commit path.
• Copilot VS Code immediate-stats regression passes with the same ai_additions == 1 expectation.
• Copied-code regression passes: a commit without any agent hook reports ai_additions == 0 and keeps the new lines as unknown/untracked additions.

Broader regression sweep:

task test TEST_FILTER=stats
task test TEST_FILTER=cursor
task test TEST_FILTER=github_copilot

Expected outcome: stats, Cursor, and GitHub Copilot integration coverage pass with the daemon sync behavior enabled.

Additional whitespace check:

git diff --check origin/main..siddhant/cursor-copilot-commit-stats-regressions

Expected outcome: no output and exit code 0.

Docs

No docs change needed. This fixes timing of existing git-ai stats / git-ai status behavior and is covered by regression tests.

Notes

Draft PR for focused review and CI validation.