Use the number prefix to find the right spec

scripts/bash/common.sh

@@ -83,6 +83,47 @@ check_feature_branch() {
 
 get_feature_dir() { echo "$1/specs/$2"; }
 
+# Find feature directory by numeric prefix instead of exact branch match
+# This allows multiple branches to work on the same spec (e.g., 004-fix-bug, 004-add-feature)
+find_feature_dir_by_prefix() {
+    local repo_root="$1"
+    local branch_name="$2"
+    local specs_dir="$repo_root/specs"
+
+    # Extract numeric prefix from branch (e.g., "004" from "004-whatever")
+    if [[ ! "$branch_name" =~ ^([0-9]{3})- ]]; then
+        # If branch doesn't have numeric prefix, fall back to exact match
+        echo "$specs_dir/$branch_name"
+        return
+    fi
+
+    local prefix="${BASH_REMATCH[1]}"
+
+    # Search for directories in specs/ that start with this prefix
+    local matches=()
+    if [[ -d "$specs_dir" ]]; then
+        for dir in "$specs_dir"/"$prefix"-*; do
+            if [[ -d "$dir" ]]; then
+                matches+=("$(basename "$dir")")
+            fi
+        done
+    fi
+
+    # Handle results
+    if [[ ${#matches[@]} -eq 0 ]]; then
+        # No match found - return the branch name path (will fail later with clear error)
+        echo "$specs_dir/$branch_name"
+    elif [[ ${#matches[@]} -eq 1 ]]; then
+        # Exactly one match - perfect!
+        echo "$specs_dir/${matches[0]}"
+    else
+        # Multiple matches - this shouldn't happen with proper naming convention
+        echo "ERROR: Multiple spec directories found with prefix '$prefix': ${matches[*]}" >&2
+        echo "Please ensure only one spec directory exists per numeric prefix." >&2
+        echo "$specs_dir/$branch_name"  # Return something to avoid breaking the script
+    fi
+}
+
 get_feature_paths() {
     local repo_root=$(get_repo_root)
     local current_branch=$(get_current_branch)
@@ -92,7 +133,8 @@ get_feature_paths() {
         has_git_repo="true"
     fi
 
-    local feature_dir=$(get_feature_dir "$repo_root" "$current_branch")
+    # Use prefix-based lookup to support multiple branches per spec
+    local feature_dir=$(find_feature_dir_by_prefix "$repo_root" "$current_branch")
 
     cat <<EOF
 REPO_ROOT='$repo_root'