TASK-007: View commit history and changes

Status: planned — depends on TASK-004 and TASK-006 Owner: Codex Reviewer: Claude

Outcome

A user can inspect commit history, changed files, per-commit patches, and comparisons between refs in a read-only interface.

Commit history supports pagination and clearly identifies the active ref.
Commit details show metadata and changed files without exposing private data in logs.
Added, modified, renamed, and deleted files are distinguished.
Large or truncated diffs are explicitly identified and bounded for mobile rendering.
Ref comparisons validate and encode both refs independently.
Tests cover change mapping, rename/delete behavior, pagination, truncation, and error states.