docs: restore full upstream integration rules and PR workflow to CLAUDE.md

Author: RandomCrocodile

CLAUDE.md

@@ -75,13 +75,43 @@ main      — stable, releases only
 
 ## Upstream Integration Rules (MANDATORY)
 
-Before cherry-picking ANY change from `mkaring/ConfuserEx`:
+Before cherry-picking or adapting ANY change from `mkaring/ConfuserEx`:
 
-1. **Verify the issue/PR is still open and relevant**
-2. **Only work on OPEN issues and PRs**
-3. **Review the actual diff** — do NOT blindly cherry-pick
-4. **Analyse code quality** — check for regressions and edge cases
-5. **Close issues already implemented** in our fork
+### 1. Verify status first
+
+- Check `gh issue view <number> --repo mkaring/ConfuserEx` for current status
+- Check if a fix was already merged upstream after the issue was filed
+- If the issue is closed/fixed upstream, verify our fork already has the fix
+- Close our corresponding issue if already resolved
+- **Only work on OPEN issues and PRs** — skip closed, wontfix, duplicate, invalid
+
+### 2. Review the actual code
+
+- Fetch the PR: `git fetch mkaring pull/<number>/head:pr-<number>`
+- Read the actual diff, not just the title
+- Check if the change conflicts with our existing modifications
+- Test that the cherry-pick applies cleanly
+- **Do NOT blindly cherry-pick — understand what the code does first**
+
+### 3. Analyse code quality
+
+- Review for correctness, not just intent
+- Check for regressions, missing edge cases, or poor patterns
+- Verify the fix actually solves the stated problem
+- Check if there's a better approach than the upstream PR
+
+### 4. When creating issues from upstream
+
+- Create matching issues on both private and public repos
+- Reference the upstream issue number in the description
+- Mention the original reporter when posting fixes
+- Tag with appropriate labels (enhancement, bug, upstream)
+
+### 5. PR iteration rules
+
+- Always push fixes to the **same branch** — never create replacement PRs
+- When a PR gets review feedback, push additional commits to the same branch
+- When a tester reports issues, fix on the same branch and ask for re-test
 
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