feat(code): add /code:compare for module version comparison (#115)

Add compare command that:
- Compares local vs remote module versions
- Shows status (ahead, behind, synced)
- Checks dependency compatibility with Composer constraints
- Supports ^ and ~ version operators
- Suggests deployment order for incompatible versions

Migrated from core-claude PR #59.

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

claude/code/commands/compare.md

@@ -0,0 +1,169 @@
+---
+name: compare
+description: Compare versions between modules and find incompatibilities
+args: "[module] [--prod]"
+---
+
+# Compare Module Versions
+
+Compares local module versions against remote, and checks for dependency conflicts.
+
+## Usage
+
+```
+/code:compare                 # Compare all modules
+/code:compare core-tenant     # Compare specific module
+/code:compare --prod          # Compare with production
+```
+
+## Action
+
+```bash
+#!/bin/bash
+
+# Function to compare semantic versions
+# Returns:
+#   0 if versions are equal
+#   1 if version1 > version2
+#   2 if version1 < version2
+compare_versions() {
+    if [ "$1" == "$2" ]; then
+        return 0
+    fi
+    local winner=$(printf "%s\n%s" "$1" "$2" | sort -V | tail -n 1)
+    if [ "$winner" == "$1" ]; then
+        return 1
+    else
+        return 2
+    fi
+}
+
+# Checks if a version is compatible with a Composer constraint.
+is_version_compatible() {
+    local version=$1
+    local constraint=$2
+    local base_version
+    local operator=""
+
+    if [[ $constraint == \^* ]]; then
+        operator="^"
+        base_version=${constraint:1}
+    elif [[ $constraint == ~* ]]; then
+        operator="~"
+        base_version=${constraint:1}
+    else
+        base_version=$constraint
+        compare_versions "$version" "$base_version"
+        if [ $? -eq 2 ]; then return 1; else return 0; fi
+    fi
+
+    compare_versions "$version" "$base_version"
+    if [ $? -eq 2 ]; then
+        return 1
+    fi
+
+    local major minor patch
+    IFS='.' read -r major minor patch <<< "$base_version"
+    local upper_bound
+
+    if [ "$operator" == "^" ]; then
+        if [ "$major" -gt 0 ]; then
+            upper_bound="$((major + 1)).0.0"
+        elif [ "$minor" -gt 0 ]; then
+            upper_bound="0.$((minor + 1)).0"
+        else
+            upper_bound="0.0.$((patch + 1))"
+        fi
+    elif [ "$operator" == "~" ]; then
+        upper_bound="$major.$((minor + 1)).0"
+    fi
+
+    compare_versions "$version" "$upper_bound"
+    if [ $? -eq 2 ]; then
+        return 0
+    else
+        return 1
+    fi
+}
+
+# Parse arguments
+TARGET_MODULE=""
+ENV_FLAG=""
+for arg in "$@"; do
+  case $arg in
+    --prod)
+      ENV_FLAG="--prod"
+      ;;
+    *)
+      if [[ ! "$arg" == --* ]]; then
+        TARGET_MODULE="$arg"
+      fi
+      ;;
+  esac
+done
+
+# Get module health data
+health_data=$(core dev health $ENV_FLAG)
+
+module_data=$(echo "$health_data" | grep -vE '^(Module|━━|Comparing)' | sed '/^$/d' || true)
+if [ -z "$module_data" ]; then
+  echo "No module data found."
+  exit 0
+fi
+
+mapfile -t module_lines <<< "$module_data"
+remote_versions=$(echo "$module_data" | awk '{print $1, $3}')
+
+echo "Module Version Comparison"
+echo "━━━━━━━━━━━━━━━━━━━━━━━━━"
+echo ""
+echo "Module          Local     Remote    Status"
+echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+
+for line in "${module_lines[@]}"; do
+  read -r module local_version remote_version _ <<< "$line"
+  if [ -n "$TARGET_MODULE" ] && [ "$module" != "$TARGET_MODULE" ]; then
+    continue
+  fi
+
+  compare_versions "$local_version" "$remote_version"
+  case $? in
+    0) status="✓" ;;
+    1) status="↑ ahead" ;;
+    2) status="↓ behind" ;;
+  esac
+
+  printf "%-15s %-9s %-9s %s\n" "$module" "$local_version" "$remote_version" "$status"
+done
+
+echo ""
+echo "Dependency Check:"
+
+for line in "${module_lines[@]}"; do
+  read -r module _ <<< "$line"
+  if [ -n "$TARGET_MODULE" ] && [ "$module" != "$TARGET_MODULE" ]; then
+    continue
+  fi
+
+  if [ -f "$module/composer.json" ]; then
+    dependencies=$(jq -r '.require? | select(. != null) | to_entries[] | "\(.key)@\(.value)"' "$module/composer.json")
+
+    for dep in $dependencies; do
+      dep_name=$(echo "$dep" | cut -d'@' -f1)
+      dep_constraint=$(echo "$dep" | cut -d'@' -f2)
+
+      remote_version=$(echo "$remote_versions" | grep "^$dep_name " | awk '{print $2}')
+
+      if [ -n "$remote_version" ]; then
+        if ! is_version_compatible "$remote_version" "$dep_constraint"; then
+          echo "⚠ $module requires $dep_name $dep_constraint"
+          echo "  But production has $remote_version (incompatible)"
+          echo "  Either:"
+          echo "  - Deploy a compatible version of $dep_name first"
+          echo "  - Or adjust the dependency in $module"
+        fi
+      fi
+    done
+  fi
+done
+```