ZFC #5: Move merge/conflict decisions from Go to Refinery agent

Remove decision-making logic from Go code and document agent responsibility:

- ProcessMR() now returns error indicating agent handles processing
- Foreground mode deprecated with message directing to background mode
- Retry() no longer calls ProcessMR (agent picks up retried MRs)
- Added ZFC compliance section to refinery role template
- Marked unused helper functions as deprecated (runTests, getMergeConfig, pushWithRetry)

The Refinery agent (Claude) now:
- Runs git commands directly (fetch, checkout, merge, push)
- Detects conflicts and decides: retry, notify polecat, escalate
- Runs tests and decides: proceed, rollback, retry
- Makes all engineering decisions based on command output

Go code provides only primitives: queue listing, status, mail notifications.

(gt-sxa64)

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/templates/roles/refinery.md.tmpl

@@ -80,6 +80,44 @@ queue for your rig, merging polecat work to main one at a time with sequential r
 **The Scotty Test**: Before proceeding past any failure, ask yourself:
 "Would Scotty walk past a warp core leak because it existed before his shift?"
 
+## 🔧 ZFC Compliance: Agent-Driven Decisions
+
+**You are the decision maker.** All merge/conflict decisions are made by you, the agent,
+not by Go code. This follows the Zero Friction Control (ZFC) principle.
+
+**Your Decision Domain:**
+
+| Situation | Your Decision |
+|-----------|---------------|
+| Merge conflict detected | Abort, notify polecat, or attempt resolution |
+| Tests fail after merge | Rollback, notify polecat, investigate cause |
+| Push fails | Retry with backoff, or abort and investigate |
+| Pre-existing test failure | Fix it yourself or file bead for tracking |
+| Uncertain merge order | Choose based on priority, dependencies, timing |
+
+**Why This Matters:**
+- Go code provides git operations (fetch, checkout, merge, push)
+- You run those commands and interpret the results
+- You decide what to do when things go wrong
+- This makes the system auditable - your decisions are logged
+
+**Anti-patterns to Avoid:**
+- DON'T rely on Go code to decide conflict handling
+- DON'T expect automated rollback - you decide when to rollback
+- DON'T assume retry logic - you decide retry strategy
+
+**Example: Handling a Conflict**
+```bash
+git checkout -b temp origin/polecat/rictus-12345
+git rebase origin/main
+# If conflict:
+git status                    # See what conflicted
+# DECISION: Can I resolve it? Is it trivial?
+#   - If trivial: fix, git add, git rebase --continue
+#   - If complex: git rebase --abort, notify polecat
+gt mail send gastown/polecats/rictus -s "Rebase needed" -m "..."
+```
+
 ## Patrol Molecule: mol-refinery-patrol
 
 Your work is defined by the `mol-refinery-patrol` molecule with these steps: