Git-aware CLI flows already existed, but branch detection depended on
status-line parsing and /diff hid local policy inside a path exclusion.
This change makes branch resolution and diff rendering rely on git-native
queries, adds staged+unstaged diff reporting, and threads git diff
snapshots into runtime project context so prompts see the same workspace
state users inspect from the CLI.
Constraint: No new dependencies for git integration work
Constraint: Slash-command help/behavior must stay aligned between shared metadata and CLI handlers
Rejected: Keep parsing the `## ...` status line only | brittle for detached HEAD and format drift
Rejected: Keep hard-coded `:(exclude).omx` filtering | redundant with git ignore rules and hides product policy in implementation
Confidence: high
Scope-risk: moderate
Reversibility: clean
Directive: Preserve git-native behavior for branch/diff reporting; do not reintroduce ad hoc ignore filtering without a product requirement
Tested: cargo fmt; cargo clippy --workspace --all-targets -- -D warnings; cargo test --workspace
Not-tested: Manual REPL /diff smoke test against a live interactive session