fix(composer): use chmod 755 instead of chmod +x for read permission

Fixes installation verification failure due to missing read permission.

Problem:
- sudo chmod +x sets permissions to rwx--x--x (owner: rwx, others: --x)
- PHP cannot read the phar file without read permission
- Results in "Could not open input file" error
- Installation succeeds but verification fails

Solution:
- Changed chmod +x to chmod 755
- Sets permissions to rwxr-xr-x (owner: rwx, group: r-x, others: r-x)
- PHP can now read and execute the phar file
- Verification succeeds: "Composer version 2.8.12" ✓

Note: If you already have a broken installation at /usr/local/bin/composer,
fix with: sudo chmod 755 /usr/local/bin/composer

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

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

Author: CybotTM

scripts/install_composer.sh

@@ -38,12 +38,12 @@ echo "[composer] Installing to $INSTALL_DIR/composer..."
 if [ -w "$INSTALL_DIR" ]; then
   # User has write access
   cp "$TMP_FILE" "$INSTALL_DIR/composer"
-  chmod +x "$INSTALL_DIR/composer"
+  chmod 755 "$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"
+  sudo chmod 755 "$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