feat: integrate claude-code-base-action as local subaction (#285)

* feat: integrate claude-code-base-action as local subaction

- Copy claude-code-base-action into base-action/ directory
- Update action.yml to reference ./base-action instead of external repo
- Preserve complete base action structure for future refactoring

This eliminates the external dependency while maintaining modularity.

* feat: consolidate CI workflows and add version bump workflow

- Move base-action test workflows to main .github/workflows/
- Update workflow references to use ./base-action
- Add CI jobs for base-action (test, typecheck, prettier)
- Add bump-claude-code-version workflow for base-action
- Remove redundant .github directory from base-action

This consolidates all CI workflows in one place while maintaining
full test coverage for both the main action and base-action.

* tsc

* copy again

* fix tests

* fix: use absolute path for base-action reference

Replace relative path ./base-action with ${{ github.action_path }}/base-action
to ensure the action works correctly when used in other repositories.

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

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

* fix: inline base-action execution to support usage in other repos

Replace uses: ./base-action with direct shell execution since GitHub Actions
doesn't support dynamic paths in composite actions. This ensures the action
works correctly when used in other repositories.

Changes:
- Install Claude Code globally before execution
- Run base-action's index.ts directly with bun
- Pass all required INPUT_* environment variables
- Maintain base-action for future separate publishing

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

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

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

base-action/test/mcp-test/.npmrc

@@ -0,0 +1,2 @@
+engine-strict=true
+registry=https://registry.npmjs.org/