feat: add mandatory acknowledgment comment when claude starts work #21

Modified the prompt in client/src/claude-client.ts to enforce posting
an initial comment when Claude begins working on an issue. This provides
immediate feedback to users.

Changes:
- Added mandatory step 4 in prompt that requires posting acknowledgment
- Comment must mention the issue creator (@username)
- Must be posted before any actual work begins
- Includes brief statement about starting work and optional plan

This ensures humans get immediate feedback when their issue is picked up.

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

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

client/src/claude-client.ts

@@ -70,7 +70,14 @@ Before you start any work on this issue, you MUST complete these steps IN ORDER:
    - ALL comments in the discussion thread (chronologically)
    - The full context and conversation history
 
-4. ONLY AFTER reading everything above, proceed with your work
+4. **IMMEDIATELY** post a comment using mcp__gogs__create_issue_comment to acknowledge you've started working:
+   - Mention the issue creator (@${issue.pusher}) in the comment
+   - Briefly state that you're starting work on the issue
+   - Optionally include a high-level plan of what you'll do
+   - This MUST be done before any other work (code changes, analysis, etc.)
+   - Example: "@${issue.pusher} I'm starting work on this issue now! I'll [brief description of approach]"
+
+5. ONLY AFTER posting the acknowledgment comment, proceed with your work
 
 === ISSUE CONTEXT ===