feat(composer): switch from apt to binary installation method

Changes installation method from package_manager to dedicated binary installer.

Why:
- apt version lags behind (2.7.1 vs 2.8.12)
- Binary installation is the official recommended method
- Provides access to latest stable releases

Changes:
- catalog/composer.json:
  * install_method: package_manager → dedicated_script
  * Added script: install_composer.sh
  * Added github_repo for version tracking
  * Removed package manager definitions

- scripts/install_composer.sh: NEW
  * Downloads latest stable phar from getcomposer.org
  * Verifies phar validity with PHP
  * Installs to /usr/local/bin/composer (requires sudo)
  * Supports COMPOSER_INSTALL_DIR env var for custom location
  * Provides clear error messages and installation feedback

Installation:
  $ scripts/install_tool.sh composer update

Binary will be installed to /usr/local/bin/composer which takes
precedence over /usr/bin/composer (apt version), automatically
preferring the newer binary installation.

Reference: https://getcomposer.org/doc/faqs/how-to-install-composer-programmatically.md

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: CybotTM

catalog/composer.json

@@ -1,13 +1,10 @@
 {
   "name": "composer",
-  "install_method": "package_manager",
+  "install_method": "dedicated_script",
   "description": "PHP dependency manager",
   "homepage": "https://getcomposer.org/",
+  "github_repo": "composer/composer",
   "binary_name": "composer",
-  "packages": {
-    "apt": "composer",
-    "brew": "composer",
-    "dnf": "composer",
-    "pacman": "composer"
-  }
+  "script": "install_composer.sh",
+  "notes": "Installed from latest stable phar (https://getcomposer.org/download/latest-stable/composer.phar). Requires PHP."
 }

scripts/install_composer.sh

@@ -0,0 +1,62 @@
+#!/usr/bin/env bash
+# Dedicated installer for Composer
+# Downloads latest stable composer.phar and installs to /usr/local/bin
+set -euo pipefail
+
+INSTALL_DIR="${COMPOSER_INSTALL_DIR:-/usr/local/bin}"
+COMPOSER_URL="https://getcomposer.org/download/latest-stable/composer.phar"
+
+echo "[composer] Downloading latest stable composer.phar..."
+
+# Download to temp file
+TMP_FILE="$(mktemp)"
+trap "rm -f '$TMP_FILE'" EXIT
+
+if ! curl -fsSL "$COMPOSER_URL" -o "$TMP_FILE"; then
+  echo "[composer] Error: Failed to download from $COMPOSER_URL" >&2
+  exit 1
+fi
+
+# Verify it's a valid phar by checking version
+echo "[composer] Verifying downloaded phar..."
+if ! php "$TMP_FILE" --version >/dev/null 2>&1; then
+  echo "[composer] Error: Downloaded file is not a valid composer.phar" >&2
+  exit 1
+fi
+
+# Get version
+COMPOSER_VERSION="$(php "$TMP_FILE" --version 2>/dev/null | head -1 || echo 'unknown')"
+echo "[composer] Downloaded: $COMPOSER_VERSION"
+
+# Get current version
+CURRENT_VERSION="$(command -v composer >/dev/null 2>&1 && composer --version 2>/dev/null | head -1 || echo '<none>')"
+echo "[composer] Current: $CURRENT_VERSION"
+
+# Install composer.phar
+echo "[composer] Installing to $INSTALL_DIR/composer..."
+
+if [ -w "$INSTALL_DIR" ]; then
+  # User has write access
+  cp "$TMP_FILE" "$INSTALL_DIR/composer"
+  chmod +x "$INSTALL_DIR/composer"
+elif command -v sudo >/dev/null 2>&1; then
+  # Need sudo
+  echo "[composer] Requires sudo to install to $INSTALL_DIR"
+  sudo cp "$TMP_FILE" "$INSTALL_DIR/composer"
+  sudo chmod +x "$INSTALL_DIR/composer"
+else
+  echo "[composer] Error: Cannot write to $INSTALL_DIR and sudo not available" >&2
+  echo "[composer] Try: COMPOSER_INSTALL_DIR=~/.local/bin $0" >&2
+  exit 1
+fi
+
+# Verify installation
+NEW_VERSION="$(composer --version 2>/dev/null | head -1 || echo '<failed>')"
+echo "[composer] Installed: $NEW_VERSION"
+
+if [ "$NEW_VERSION" = "<failed>" ]; then
+  echo "[composer] Error: Installation verification failed" >&2
+  exit 1
+fi
+
+echo "[composer] ✓ Installation successful"