feat: Git extension stage 2 — GIT_BRANCH_NAME override, --force for existing dirs, auto-install tests (#1940) (#2117)

* feat: Git extension stage 2 — GIT_BRANCH_NAME override, --force for existing dirs, auto-install tests (#1940)

- Add GIT_BRANCH_NAME env var override to create-new-feature.sh/.ps1
  for exact branch naming (bypasses all prefix/suffix generation)
- Fix --force flag for 'specify init <dir>' into existing directories
- Add TestGitExtensionAutoInstall tests (auto-install, --no-git skip,
  commands registered)
- Add TestFeatureDirectoryResolution tests (env var, feature.json,
  priority, branch fallback)
- Document GIT_BRANCH_NAME in speckit.git.feature.md and specify.md

* fix: remove unused Tuple import (ruff F401)

* fix: address Copilot review feedback (#2117)

- Fix timestamp regex ordering: check YYYYMMDD-HHMMSS before generic
  numeric prefix in both bash and PowerShell
- Set BRANCH_SUFFIX in GIT_BRANCH_NAME override path so 244-byte
  truncation logic works correctly
- Add 244-byte length check for GIT_BRANCH_NAME in PowerShell
- Use existing_items for non-empty dir warning with --force
- Skip git extension install if already installed (idempotent --force)
- Wrap PowerShell feature.json parsing in try/catch for malformed JSON
- Fix PS comment: 'prefix lookup' -> 'exact mapping via Get-FeatureDir'
- Remove non-functional SPECIFY_SPEC_DIRECTORY from specify.md template

* fix: address second round of Copilot review feedback (#2117)

- Guard shutil.rmtree on init failure: skip cleanup when --force merged
  into a pre-existing directory (prevents data loss)
- Bash: error on GIT_BRANCH_NAME >244 bytes instead of broken truncation
- Fix malformed numbered list in specify.md (restore missing step 1)
- Add claude_skills.exists() assert before iterdir() in test

* fix: use UTF-8 byte count for 244-byte branch name limit (#2117)

- Bash: use LC_ALL=C wc -c for byte length instead of ${#VAR}
- PowerShell: use [System.Text.Encoding]::UTF8.GetByteCount() instead
  of .Length (UTF-16 code units)

* fix: address third round of review feedback (#2117)

- Update --dry-run help text in bash and PowerShell (branch name only)
- Fix specify.md JSON example: use concrete path, not literal variable
- Add TestForceExistingDirectory tests (merge + error without --force)
- Add PowerShell Get-FeaturePathsEnv tests (env var + feature.json)

* fix: normalize relative paths and fix Test-HasGit compat (#2117)

- Bash common.sh: normalize SPECIFY_FEATURE_DIRECTORY and feature.json
  relative paths to absolute under repo root
- PowerShell common.ps1: same normalization using IsPathRooted + Join-Path
- PowerShell create-new-feature.ps1: call Test-HasGit without -RepoRoot
  for compatibility with core common.ps1 (no param) and git-common.ps1
  (optional param with default)

* test: add GIT_BRANCH_NAME automated tests for bash and PowerShell (#2117)

- TestGitBranchNameOverrideBash: 5 tests (exact name, sequential prefix,
  timestamp prefix, overlong rejection, dry-run)
- TestGitBranchNameOverridePowerShell: 4 tests (exact name, sequential
  prefix, timestamp prefix, overlong rejection)
- Tests use extension scripts (not core) via new ext_git_repo and
  ext_ps_git_repo fixtures

* fix: restore git init during specify init + review fixes (#2117)

- Restore is_git_repo() and init_git_repo() functions removed in stage 2
- specify init now runs git init AND installs git extension (not just
  extension install alone)
- Add is_dir() guard for non-here path to prevent uncontrolled error
  when target exists but is a file
- Add python3 JSON fallback in common.sh for multi-line feature.json
  (grep pipeline fails on pretty-printed JSON without jq)

* fix: use init_git_repo error_msg in failure output (#2117)

* fix: ensure_executable_scripts also covers .specify/extensions/ (#2117)

Extension .sh scripts (e.g. create-new-feature.sh, initialize-repo.sh)
may lack execute bits after install. Scan both .specify/scripts/ and
.specify/extensions/ for permission fixing.

* fix: move chmod after extension install + sanitize error_msg (#2117)

- ensure_executable_scripts() now runs after git extension install so
  extension .sh files get execute bits in the same init run
- Sanitize init_git_repo error_msg to single line (replace newlines,
  truncate to 120 chars) to prevent garbled StepTracker output

* fix: use tracker.error for git init/extension failures (#2117)

Git init failure and extension install failure were reported as
tracker.complete (showing green) even on error. Now track a
git_has_error flag and call tracker.error when any step fails,
so the UI correctly reflects the failure state.

* fix: sanitize ext_err in git step tracker for consistent rendering (#2117)

tests/extensions/git/test_git_extension.py

@@ -280,7 +280,6 @@ class TestCreateFeatureBash:
         assert result.returncode == 0, result.stderr
         data = json.loads(result.stdout)
         assert data["BRANCH_NAME"] == "001-user-auth"
-        assert "SPEC_FILE" in data
         assert data["FEATURE_NUM"] == "001"
 
     def test_creates_branch_timestamp(self, tmp_path: Path):
@@ -294,18 +293,6 @@ class TestCreateFeatureBash:
         data = json.loads(result.stdout)
         assert re.match(r"^\d{8}-\d{6}-feat$", data["BRANCH_NAME"])
 
-    def test_creates_spec_dir(self, tmp_path: Path):
-        """create-new-feature.sh creates specs directory and spec.md."""
-        project = _setup_project(tmp_path)
-        result = _run_bash(
-            "create-new-feature.sh", project,
-            "--json", "--short-name", "test-feat", "Test feature",
-        )
-        assert result.returncode == 0, result.stderr
-        data = json.loads(result.stdout)
-        spec_file = Path(data["SPEC_FILE"])
-        assert spec_file.exists(), f"spec.md not created at {spec_file}"
-
     def test_increments_from_existing_specs(self, tmp_path: Path):
         """Sequential numbering increments past existing spec directories."""
         project = _setup_project(tmp_path)
@@ -321,7 +308,7 @@ class TestCreateFeatureBash:
         assert data["FEATURE_NUM"] == "003"
 
     def test_no_git_graceful_degradation(self, tmp_path: Path):
-        """create-new-feature.sh works without git (creates spec dir only)."""
+        """create-new-feature.sh works without git (outputs branch name, skips branch creation)."""
         project = _setup_project(tmp_path, git=False)
         result = _run_bash(
             "create-new-feature.sh", project,
@@ -330,8 +317,8 @@ class TestCreateFeatureBash:
         assert result.returncode == 0, result.stderr
         assert "Warning" in result.stderr
         data = json.loads(result.stdout)
-        spec_file = Path(data["SPEC_FILE"])
-        assert spec_file.exists()
+        assert "BRANCH_NAME" in data
+        assert "FEATURE_NUM" in data
 
     def test_dry_run(self, tmp_path: Path):
         """--dry-run computes branch name without creating anything."""
@@ -382,7 +369,8 @@ class TestCreateFeaturePowerShell:
         json_line = [l for l in result.stdout.splitlines() if l.strip().startswith("{")]
         assert json_line, f"No JSON in output: {result.stdout}"
         data = json.loads(json_line[-1])
-        assert Path(data["SPEC_FILE"]).exists()
+        assert "BRANCH_NAME" in data
+        assert "FEATURE_NUM" in data
 
 
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