refactor: complete v1.0 simplification by removing all legacy inputs

- Remove all backward compatibility for v1.0 simplification
- Remove 10 legacy inputs from base-action/action.yml
- Remove 9 legacy inputs from main action.yml
- Simplify ClaudeOptions type to just timeoutMinutes and claudeArgs
- Remove all legacy option handling from prepareRunConfig
- Update tests to remove references to deleted fields
- Remove obsolete test file github/context.test.ts
- Clean up types to remove customInstructions, allowedTools, disallowedTools

Users now use claudeArgs exclusively for CLI control.

examples/claude-review-from-author.yml

@@ -23,11 +23,11 @@ jobs:
           fetch-depth: 1
 
       - name: Review PR from Specific Author
-        uses: anthropics/claude-code-action@beta
+        uses: anthropics/claude-code-action@v1
         with:
           anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
           timeout_minutes: "60"
-          direct_prompt: |
+          prompt: |
             Please provide a thorough review of this pull request.
 
             Since this is from a specific author that requires careful review,