feat: check remote branches to prevent duplicate branch numbers

- Add --number parameter to create-new-feature scripts (bash & PowerShell)
- Add check_existing_branches() function to fetch and scan remote branches
- Update branch numbering logic to check remotes before creating new branches
- Update /speckit.specify command to document remote branch checking workflow
- Prevents duplicate branch numbers when branches exist on remotes but not locally
- Maintains backward compatibility with existing workflows
- Falls back to local directory scanning when Git is not available

scripts/powershell/create-new-feature.ps1

@@ -4,6 +4,7 @@
 param(
     [switch]$Json,
     [string]$ShortName,
+    [int]$Number = 0,
     [switch]$Help,
     [Parameter(ValueFromRemainingArguments = $true)]
     [string[]]$FeatureDescription
@@ -12,11 +13,12 @@ $ErrorActionPreference = 'Stop'
 
 # Show help if requested
 if ($Help) {
-    Write-Host "Usage: ./create-new-feature.ps1 [-Json] [-ShortName <name>] <feature description>"
+    Write-Host "Usage: ./create-new-feature.ps1 [-Json] [-ShortName <name>] [-Number N] <feature description>"
     Write-Host ""
     Write-Host "Options:"
     Write-Host "  -Json               Output in JSON format"
     Write-Host "  -ShortName <name>   Provide a custom short name (2-4 words) for the branch"
+    Write-Host "  -Number N           Specify branch number manually (overrides auto-detection)"
     Write-Host "  -Help               Show this help message"
     Write-Host ""
     Write-Host "Examples:"
@@ -56,6 +58,45 @@ function Find-RepositoryRoot {
         $current = $parent
     }
 }
+
+function Get-NextBranchNumber {
+    param(
+        [string]$ShortName
+    )
+    
+    # Fetch all remotes to get latest branch info (suppress errors if no remotes)
+    try {
+        git fetch --all --prune 2>$null | Out-Null
+    } catch {
+        # Ignore fetch errors
+    }
+    
+    # Find all branches matching the pattern (local and remote)
+    $branches = @()
+    try {
+        $allBranches = git branch -a 2>$null
+        if ($allBranches) {
+            $branches = $allBranches | Where-Object { $_ -match "feature/(\d+)-$([regex]::Escape($ShortName))$" } | ForEach-Object {
+                if ($_ -match "feature/(\d+)-") {
+                    [int]$matches[1]
+                }
+            }
+        }
+    } catch {
+        # Ignore errors
+    }
+    
+    # Get the highest number
+    $maxNum = 0
+    foreach ($num in $branches) {
+        if ($num -gt $maxNum) {
+            $maxNum = $num
+        }
+    }
+    
+    # Return next number
+    return $maxNum + 1
+}
 $fallbackRoot = (Find-RepositoryRoot -StartDir $PSScriptRoot)
 if (-not $fallbackRoot) {
     Write-Error "Error: Could not determine repository root. Please run this script from within the repository."
@@ -79,18 +120,6 @@ Set-Location $repoRoot
 $specsDir = Join-Path $repoRoot 'specs'
 New-Item -ItemType Directory -Path $specsDir -Force | Out-Null
 
-$highest = 0
-if (Test-Path $specsDir) {
-    Get-ChildItem -Path $specsDir -Directory | ForEach-Object {
-        if ($_.Name -match '^(\d{3})') {
-            $num = [int]$matches[1]
-            if ($num -gt $highest) { $highest = $num }
-        }
-    }
-}
-$next = $highest + 1
-$featureNum = ('{0:000}' -f $next)
-
 # Function to generate branch name with stop word filtering and length filtering
 function Get-BranchName {
     param([string]$Description)
@@ -145,6 +174,27 @@ if ($ShortName) {
     $branchSuffix = Get-BranchName -Description $featureDesc
 }
 
+# Determine branch number
+if ($Number -eq 0) {
+    if ($hasGit) {
+        # Check existing branches on remotes
+        $Number = Get-NextBranchNumber -ShortName $branchSuffix
+    } else {
+        # Fall back to local directory check
+        $highest = 0
+        if (Test-Path $specsDir) {
+            Get-ChildItem -Path $specsDir -Directory | ForEach-Object {
+                if ($_.Name -match '^(\d{3})') {
+                    $num = [int]$matches[1]
+                    if ($num -gt $highest) { $highest = $num }
+                }
+            }
+        }
+        $Number = $highest + 1
+    }
+}
+
+$featureNum = ('{0:000}' -f $Number)
 $branchName = "$featureNum-$branchSuffix"
 
 # GitHub enforces a 244-byte limit on branch names