feat(ui): SPEC-V0-3-0-STATUS-BAR-WIRE-002 MS-1 — StatusBar git label graduation (placeholder → moai-git real query) (AC-SBW-7~12)

.moai/specs/SPEC-V0-3-0-STATUS-BAR-WIRE-002/progress.md

@@ -0,0 +1,82 @@
+---
+spec_id: SPEC-V0-3-0-STATUS-BAR-WIRE-002
+status: green
+methodology: tdd
+created_at: 2026-05-06
+updated_at: 2026-05-06
+---
+
+# SPEC-V0-3-0-STATUS-BAR-WIRE-002 Progress
+
+## Phase Log
+
+### RED (2026-05-06)
+
+5 fixture-based tests added to `crates/moai-studio-ui/src/lib.rs::tests` (T-SBW2 block):
+- `derive_status_git_label_clean_repo_returns_branch_no_dirty` (AC-SBW-7)
+- `derive_status_git_label_dirty_repo_returns_dirty_true` (AC-SBW-8)
+- `derive_status_git_label_non_git_directory_returns_none` (AC-SBW-9)
+- `derive_status_git_label_detached_head_returns_fixed_label` (AC-SBW-10)
+- `derive_status_git_label_missing_path_returns_none` (AC-SBW-11)
+
+Compilation failed (E0308 signature mismatch) before function body update — confirmed RED.
+
+### GREEN (2026-05-06)
+
+Changes applied:
+
+1. `crates/moai-studio-ui/Cargo.toml`: added `git2 = "0.20"` to `[dev-dependencies]` for fixture creation (`Repository::init`, `set_head_detached`). Production code uses the existing `moai-git` wrapper at `[dependencies]` line 69.
+2. `crates/moai-studio-ui/src/lib.rs`:
+   - Added `use moai_git::{GitError, GitRepo};` after the existing `moai_studio_workspace` import.
+   - Replaced `derive_status_git_label_from_workspace` body (placeholder echo → `GitRepo::open` + `current_branch` + `is_dirty`). Signature changed from `&str` to `&std::path::Path` per REQ-SBW-008.
+   - Replaced `refresh_status_git_label` to look up the active workspace by id against the in-memory `self.workspaces` Vec and pass `&ws.project_path` to the derive helper. Lookup miss → `clear_git_branch` + `cx.notify()`.
+   - Removed the two placeholder unit tests; added the five fixture-based tests above plus a `make_committed_repo` helper.
+
+First test run: 1376 passed / 1 failed (`derive_status_git_label_detached_head_returns_fixed_label`).
+
+### Spec Deviation (documented)
+
+Failure cause: `moai_git::GitRepo::current_branch()` returns `Ok("HEAD")` for a detached HEAD (libgit2's `Reference::shorthand` of the HEAD ref itself is the literal `"HEAD"`), not `Err(GitError::DetachedHead)` as REQ-SBW-010 had assumed. The spec text predicted the wrapper would surface a typed error; in practice the wrapper passes the libgit2 default through.
+
+Resolution: Extended the `match repo.current_branch()` arm to also map `Ok(name) if name == "HEAD"` to the canonical `"detached"` label. This preserves the spec's user-visible contract (status bar shows `"detached"` when HEAD is detached) without modifying the `moai-git` crate (FROZEN per spec.md §3). The `Err(GitError::DetachedHead)` arm is retained for forward compatibility in case the wrapper is later changed to return the typed error.
+
+Inline rationale comment added to the match arm (English, per CLAUDE.local.md §9). No changes to spec.md required — the public AC remains satisfied.
+
+### Verification (2026-05-06)
+
+```
+cargo build -p moai-studio-ui --tests        → OK (55.60s)
+cargo test  -p moai-studio-ui --lib          → 1377 passed; 0 failed; 0 ignored (0.61s)
+cargo clippy -p moai-studio-ui --all-targets -- -D warnings → 0 warnings
+cargo fmt --all -- --check                   → clean (1 trivial drift auto-applied)
+```
+
+Test count delta: 1374 (prior baseline) − 2 (placeholder tests removed) + 5 (fixture-based tests added) = 1377. Matches spec.md §8 prediction exactly.
+
+## Acceptance Criteria
+
+| AC | Status | Test |
+|----|--------|------|
+| AC-SBW-7 (clean repo) | PASS | `derive_status_git_label_clean_repo_returns_branch_no_dirty` |
+| AC-SBW-8 (dirty repo) | PASS | `derive_status_git_label_dirty_repo_returns_dirty_true` |
+| AC-SBW-9 (non-git dir) | PASS | `derive_status_git_label_non_git_directory_returns_none` |
+| AC-SBW-10 (detached HEAD) | PASS | `derive_status_git_label_detached_head_returns_fixed_label` |
+| AC-SBW-11 (missing path) | PASS | `derive_status_git_label_missing_path_returns_none` |
+| AC-SBW-12 (cargo gate) | PASS | clippy 0 warn / fmt clean / test 1377 PASS |
+
+6/6 AC met.
+
+## OQ Resolution
+
+- **OQ-1 (default branch matcher)**: tests use `branch == "main" || branch == "master"` OR matcher (verified working on macOS host with `init.defaultBranch=main`).
+- **OQ-2 (workspace dep vs path dep)**: not applicable — `moai-git` was already a `path` dependency at `crates/moai-studio-ui/Cargo.toml:69`. No new entry needed in `[workspace.dependencies]`. Promotion to workspace dep is a separate refactor SPEC.
+- **OQ-3 (active workspace lookup cost)**: `refresh_status_git_label` now uses `self.workspaces.iter().find(...)` (in-memory Vec, O(n)) instead of re-loading `WorkspacesStore`. Lower cost than originally feared in spec.md §9.
+
+## Files Touched
+
+- `crates/moai-studio-ui/Cargo.toml` (+5 lines: git2 dev-dep)
+- `crates/moai-studio-ui/src/lib.rs` (~+115 lines net: import, body replacement, helper rewrite, tests block)
+- `.moai/specs/SPEC-V0-3-0-STATUS-BAR-WIRE-002/spec.md` (already created in plan phase)
+- `.moai/specs/SPEC-V0-3-0-STATUS-BAR-WIRE-002/progress.md` (this file)
+
+FROZEN files honoured: `crates/moai-git/**`, `crates/moai-studio-workspace/**`, `crates/moai-studio-terminal/**`, `crates/moai-studio-ui/src/status_bar.rs`, `crates/moai-studio-ui/src/palette/registry.rs` — all untouched.