Preserve discarded patch context

src/lai_automation/git.py

@@ -115,6 +115,13 @@ class GitWorkspace:
             deleted += int(remove) if remove.isdigit() else 0
         return ChangeSummary(tuple(files), added, deleted)
 
+    def diff(self, limit: int = 12_000) -> str:
+        output = self._git("diff", "--no-ext-diff", "--unified=3").stdout
+        if len(output) <= limit:
+            return output
+        half = limit // 2
+        return output[:half] + "\n...[diff middle omitted]...\n" + output[-half:]
+
     def commit(self, report_id: int) -> str:
         self._git("add", "--all")
         self._git("commit", "-m", f"Fix failure report #{report_id}")

src/lai_automation/worker.py

@@ -120,6 +120,7 @@ class AutomationWorker:
                         report.id,
                         attempt,
                     )
+                    discarded_diff = workspace.diff()
                     workspace.restore_checkpoint(valid_checkpoint)
                     restored_state = (
                         "The last syntax-valid changes were restored. Correct them without recreating "
@@ -131,7 +132,8 @@ class AutomationWorker:
                         report,
                         RuntimeError(
                             f"{exception}\n{restored_state} Make smaller edits and run php -l on each "
-                            "changed PHP file."
+                            "changed PHP file. Reconstruct the intended application fix from this discarded "
+                            f"patch excerpt, correcting its syntax:\n{discarded_diff}"
                         ),
                     )
                     continue