fix(query): keep tool turns active until final stop

[BunsDev]

Summary

Two focused changes:

• 2add182 fix(query): keep tool turns active until final stop — extracts should_emit_turn_complete(stop, max_tokens_recovery_count) so QueryEvent::TurnComplete no longer fires on intermediate tool_use turns or on max_tokens while we're still inside the recovery window. Adds 3 unit tests covering the predicate.
• eb05e68 feat(tui): color-coded diffs in Claude Code style — diff viewer renders full-row red/green tints for removed/added lines (gutter + marker + content), brighter saturated bg on inline word-level changes, soft brand-consistent fg colors, and a single-line slate hunk header that no longer doubles the @@ prefix.

Net diff: 2 files, +186/−49.

Test plan

• cargo test -p claurst-tui — diff viewer unit + integration tests green locally
• should_emit_turn_complete unit tests cover tool_use, max_tokens (under + at recovery limit), and terminal stop reasons
• Open /changes in the TUI on a branch with mixed adds/removes and confirm:
  • removed lines show a dim red row tint across the full panel width
  • added lines show a dim green row tint
  • adjacent removed→added pairs show brighter word-level highlights on the changed words
  • hunk headers render once as @@ -X,Y +A,B @@ on a full-width slate band
  • context lines stay neutral; scrollbar still clips cleanly
• Verify the 2add182 query/turn fix against the original session-turn-complete repro

🤖 Generated with Claude Code

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.