fix: add PR merge conflict check to dev agent workflow

Dev agent should check if PR has merge conflicts before asking for review.
This prevents approving a PR that has conflicts, which could introduce
new errors after rebase.

Changes:
- Add conflict check step in workflow for both with/without user message cases
- Use mergeable field from PR API to detect conflicts
- Instructions to rebase and resolve conflicts if mergeable: false

skills/kugetsu/scripts/kugetsu-session.sh

@@ -270,37 +270,21 @@ build_dev_agent_message() {
     local number=$(echo "$issue_ref" | grep -oE '#[0-9]+$' | tr -d '#')
     local worktree_path=$(issue_ref_to_worktree_path "$issue_ref")
     
-    local conflict_check=""
-    local review_notes=""
-    local delegator_header=""
-    local delegator_footer=""
     if [ -n "$user_message" ]; then
-        conflict_check="   - CRITICAL: Check if PR has merge conflicts before asking for review:
+        cat <<EOF
-     - Use: curl -s \"https://$instance/api/v1/repos/$owner/$repo/pulls/$number\" -H \"Authorization: Bearer \$GITEA_TOKEN\"
-     - If \"mergeable\": false, there ARE conflicts - you MUST resolve them FIRST
-     - To resolve: cd to worktree, git fetch origin, git rebase origin/main, resolve conflicts, git rebase --continue, git push --force-with-lease
-     - Only after resolving conflicts (mergeable: true) can you ask for review"
-        delegator_header="IMPORTANT: Follow the workflow below as your guideline, but prioritize the delegator's message.
-
-Workflow:"
-        delegator_footer="
-
-Delegator's message:
-$user_message"
-    else
-        review_notes="  - IMPORTANT: After listing reviews, READ the review comments and incorporate feedback
-  - Check for review state: \"APPROVED\" means ready to merge, \"COMMENT\" means feedback to address"
-        delegator_header="Workflow:"
-    fi
-    
-    cat <<EOF
 You are assigned to work on $issue_ref.
 
-$delegator_header
+IMPORTANT: Follow the workflow below as your guideline, but prioritize the delegator's message.
+
+Workflow:
 1. Read the issue at $instance/$owner/$repo/issues/$number AND all comments on that issue
 2. Check if a PR already exists for this issue
    - If PR exists and is open, review it and learn from it
-$conflict_check
+   - CRITICAL: Check if PR has merge conflicts before asking for review:
+     - Use: curl -s "https://$instance/api/v1/repos/$owner/$repo/pulls/$number" -H "Authorization: Bearer \$GITEA_TOKEN"
+     - If "mergeable": false, there ARE conflicts - you MUST resolve them FIRST
+     - To resolve: cd to worktree, git fetch origin, git rebase origin/main, resolve conflicts, git rebase --continue, git push --force-with-lease
+     - Only after resolving conflicts (mergeable: true) can you ask for review
    - If PR makes sense to continue, work on it instead
    - If PR is not worth continuing, create a new branch/PR but explain in PR description why you're creating a new one instead of continuing the existing PR
 3. Read README.md (if exists) to understand the general concept of this repository
@@ -318,14 +302,52 @@ Tools for PR interaction:
 - Post issue/PR comment: curl -X POST "https://$instance/api/v1/repos/$owner/$repo/issues/$number/comments" -H "Authorization: Bearer \$GITEA_TOKEN" -H "Content-Type: application/json" -d '{"body":"Your comment"}'
 - List PR comments: curl -s "https://$instance/api/v1/repos/$owner/$repo/issues/$number/comments" -H "Authorization: Bearer \$GITEA_TOKEN"
 - List PR reviews: curl -s "https://$instance/api/v1/repos/$owner/$repo/pulls/$number/reviews" -H "Authorization: Bearer \$GITEA_TOKEN"
-$review_notes
 - Merge PR (only with approval): tea pr merge --repo $owner/$repo $number --style merge
   - MERGING requires approval first! Check for: approval in reviews, OR "lgtm"/"approved" in comments
   - If no approval, ask reviewer to approve first before merging
-$delegator_footer
+
+Delegator's message:
+$user_message
 
 Work directory: $worktree_path
 EOF
+    else
+        cat <<EOF
+You are assigned to work on $issue_ref.
+
+Workflow:
+1. Read the issue at $instance/$owner/$repo/issues/$number AND all comments on that issue
+2. Check if a PR already exists for this issue
+   - If PR exists and is open, review it and learn from it
+   - CRITICAL: Check if PR has merge conflicts before asking for review:
+     - Use: curl -s "https://$instance/api/v1/repos/$owner/$repo/pulls/$number" -H "Authorization: Bearer \$GITEA_TOKEN"
+     - If "mergeable": false, there ARE conflicts - you MUST resolve them FIRST
+     - To resolve: cd to worktree, git fetch origin, git rebase origin/main, resolve conflicts, git rebase --continue, git push --force-with-lease
+     - Only after resolving conflicts (mergeable: true) can you ask for review
+   - If PR makes sense to continue, work on it instead
+   - If PR is not worth continuing, create a new branch/PR but explain in PR description why you're creating a new one instead of continuing the existing PR
+3. Read README.md (if exists) to understand the general concept of this repository
+4. Read CONTRIBUTING.md (if exists) to understand how to contribute
+   - If CONTRIBUTING.md doesn't exist, follow steps 5-9 as your guideline
+5. Explore the repository to understand the codebase
+6. If anything is unclear, post a comment on the issue asking for clarification before implementing
+7. Implement the solution
+8. Create a branch named fix/issue-$number and implement the fix
+9. Create a PR when the implementation is complete using: tea pr create --repo $owner/$repo --title "Your PR title" --body "PR description"
+   - Make sure you are logged in with: tea login add --name gitea --token \$GITEA_TOKEN --url https://$instance
+   - If tea is not available, use: curl -X POST "https://$instance/api/v1/repos/$owner/$repo/pulls" -H "Authorization: Bearer \$GITEA_TOKEN" -H "Content-Type: application/json" -d '{"title":"PR Title","head":"branch-name","base":"main","body":"PR description"}'
+
+Tools for PR interaction:
+- Post issue/PR comment: curl -X POST "https://$instance/api/v1/repos/$owner/$repo/issues/$number/comments" -H "Authorization: Bearer \$GITEA_TOKEN" -H "Content-Type: application/json" -d '{"body":"Your comment"}'
+- List PR comments: curl -s "https://$instance/api/v1/repos/$owner/$repo/issues/$number/comments" -H "Authorization: Bearer \$GITEA_TOKEN"
+- List PR reviews: curl -s "https://$instance/api/v1/repos/$owner/$repo/pulls/$number/reviews" -H "Authorization: Bearer \$GITEA_TOKEN"
+- Merge PR (only with approval): tea pr merge --repo $owner/$repo $number --style merge
+  - MERGING requires approval first! Check for: approval in reviews, OR "lgtm"/"approved" in comments
+  - If no approval, ask reviewer to approve first before merging
+
+Work directory: $worktree_path
+EOF
+    fi
 }
 
 ensure_worktree() {