feat: add path_to_claude_code_executable input for custom Claude Code… (#480)

* feat: add path_to_claude_code_executable input for custom Claude Code installations

Adds optional input to specify a custom Claude Code executable path, bypassing automatic installation. This enables:
- Using pre-installed Claude Code binaries
- Testing with specific versions for debugging
- Custom installation paths in unique environments

Includes warning that older versions may cause compatibility issues with new features.

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

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

* test: add workflow to test custom Claude Code executable path

Adds test workflow that:
- Manually installs Claude Code via install script
- Uses the new path_to_claude_code_executable input
- Verifies the custom executable path works correctly
- Validates output and execution success

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

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

---------

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

base-action/action.yml

@@ -87,6 +87,10 @@ inputs:
     description: "Whether to use Node.js dependency caching (set to true only for Node.js projects with lock files)"
     required: false
     default: "false"
+  path_to_claude_code_executable:
+    description: "Optional path to a custom Claude Code executable. If provided, skips automatic installation and uses this executable instead. WARNING: Using an older version may cause problems if the action begins taking advantage of new Claude Code features. This input is typically not needed unless you're debugging something specific or have unique needs in your environment."
+    required: false
+    default: ""
 
 outputs:
   conclusion:
@@ -118,7 +122,16 @@ runs:
 
     - name: Install Claude Code
       shell: bash
-      run: curl -fsSL https://claude.ai/install.sh | bash -s 1.0.90
+      run: |
+        if [ -z "${{ inputs.path_to_claude_code_executable }}" ]; then
+          echo "Installing Claude Code..."
+          curl -fsSL https://claude.ai/install.sh | bash -s 1.0.90
+        else
+          echo "Using custom Claude Code executable: ${{ inputs.path_to_claude_code_executable }}"
+          # Add the directory containing the custom executable to PATH
+          CLAUDE_DIR=$(dirname "${{ inputs.path_to_claude_code_executable }}")
+          echo "$CLAUDE_DIR" >> "$GITHUB_PATH"
+        fi
 
     - name: Run Claude Code Action
       shell: bash
@@ -147,6 +160,7 @@ runs:
         INPUT_CLAUDE_ENV: ${{ inputs.claude_env }}
         INPUT_FALLBACK_MODEL: ${{ inputs.fallback_model }}
         INPUT_EXPERIMENTAL_SLASH_COMMANDS_DIR: ${{ inputs.experimental_slash_commands_dir }}
+        INPUT_PATH_TO_CLAUDE_CODE_EXECUTABLE: ${{ inputs.path_to_claude_code_executable }}
 
         # Provider configuration
         ANTHROPIC_API_KEY: ${{ inputs.anthropic_api_key }}