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>

---------

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

base-action/tsconfig.json

@@ -0,0 +1,30 @@
+{
+  "compilerOptions": {
+    // Environment setup & latest features
+    "lib": ["ESNext"],
+    "target": "ESNext",
+    "module": "ESNext",
+    "moduleDetection": "force",
+    "jsx": "react-jsx",
+    "allowJs": true,
+
+    // Bundler mode (Bun-specific)
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "verbatimModuleSyntax": true,
+    "noEmit": true,
+
+    // Best practices
+    "strict": true,
+    "skipLibCheck": true,
+    "noFallthroughCasesInSwitch": true,
+    "noUncheckedIndexedAccess": true,
+
+    // Some stricter flags
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noPropertyAccessFromIndexSignature": false
+  },
+  "include": ["src/**/*", "test/**/*"],
+  "exclude": ["node_modules", "test/mcp-test"]
+}