create-new-feature.ps1 missing git branch creation

[AhmedEssa1]

Bug Description

The /specify command (via create-new-feature.ps1) generates a branch name and creates the feature directory structure, but does not create the actual git branch.

Expected Behavior

When running /specify add user authentication, the script should:

1. ✅ Generate branch name (e.g., 001-user-authentication)
2. ✅ Create specs/001-user-authentication/ directory
3. ✅ Create specs/001-user-authentication/spec.md
4. ✅ Save to .specify/feature.json
5. ❌ MISSING: Create and checkout git branch with git checkout -b 001-user-authentication

Actual Behavior

Only steps 1-4 happen. The git branch is never created. Users remain on their current branch (e.g., master or main).

Environment

• Spec Kit version: 0.11.0
• OS: Windows 11
• Script: .specify/scripts/powershell/create-new-feature.ps1

Root Cause

In create-new-feature.ps1 (line 212), after Save-FeatureJson is called, there is no git checkout -b invocation. The Get-CurrentBranch function in common.ps1 only reads from environment variables or .specify/feature.json — it's a virtual branch, not a real git branch.

Suggested Fix

Add after Save-FeatureJson call (around line 212):

# Create git branch for the new feature
try {
    $existingBranches = & git branch --list $branchName 2>$null
    if ($existingBranches) {
        Write-Warning "[specify] Git branch '$branchName' already exists. Checking it out..."
        & git checkout $branchName 2>$null | Out-Null
    } else {
        & git checkout -b $branchName 2>$null | Out-Null
        Write-Output "[specify] Created and checked out git branch: $branchName"
    }
} catch {
    Write-Warning "[specify] Failed to create git branch: $_"
}

This handles:

• New branch creation
• Existing branch checkout (idempotent)
• Error handling if git is unavailable

Impact

Users following Spec-Driven Development workflows expect each feature to be isolated in its own git branch. Without automatic branch creation, users must manually run git checkout -b <branch-name> after every /specify command, which is error-prone and breaks the expected workflow.