fix(translate): CR1-CR2 migration + H1-H4 code review bugs

CR1: Add needs_review, language_overridden to translation_languages migration
CR2: Add per_language_metrics to translation_metric_snapshots migration
H1: BulkFindReplaceService.preview() now uses replacement_text (not find pattern)
H2: get_run_records now includes per-language data via selectinload
H3: Preview per-language approve/reject uses correct (jobId, rowId, lang) args
H4: _compute_config_hash now includes target_languages

backend/src/api/routes/translate/_run_routes.py

@@ -507,6 +507,7 @@ async def bulk_find_replace(
                 run_id=run_id,
                 pattern=payload.find_pattern,
                 is_regex=payload.is_regex,
+                replacement_text=payload.replacement_text,
                 target_language=payload.target_language,
             )
             return {

backend/src/plugins/translate/__tests__/test_orchestrator.py

@@ -548,9 +548,10 @@ class TestTranslationOrchestrator:
         record.status = "SUCCESS"
         record.error_message = None
         record.created_at = datetime.now(UTC)
+        record.languages = []
 
-        db.query.return_value.filter.return_value.count.return_value = 1
-        db.query.return_value.filter.return_value.order_by.return_value.offset.return_value.limit.return_value.all.return_value = [record]
+        db.query.return_value.options.return_value.filter.return_value.count.return_value = 1
+        db.query.return_value.options.return_value.filter.return_value.order_by.return_value.offset.return_value.limit.return_value.all.return_value = [record]
 
         orch = TranslationOrchestrator(db, config_manager, "test-user")
         result = orch.get_run_records("run-1")

backend/src/plugins/translate/orchestrator.py

@@ -23,7 +23,7 @@ from collections.abc import Callable
 from datetime import UTC, datetime
 from typing import Any
 
-from sqlalchemy.orm import Session
+from sqlalchemy.orm import Session, selectinload
 
 from ...core.config_manager import ConfigManager
 from ...core.logger import belief_scope, logger
@@ -827,8 +827,10 @@ class TranslationOrchestrator:
         status_filter: str | None = None,
     ) -> dict[str, Any]:
         with belief_scope("TranslationOrchestrator.get_run_records"):
-            query = self.db.query(TranslationRecord).filter(
-                TranslationRecord.run_id == run_id
+            query = (
+                self.db.query(TranslationRecord)
+                .options(selectinload(TranslationRecord.languages))
+                .filter(TranslationRecord.run_id == run_id)
             )
 
             if status_filter:
@@ -856,6 +858,17 @@ class TranslationOrchestrator:
                         "status": r.status,
                         "error_message": r.error_message,
                         "created_at": r.created_at.isoformat() if r.created_at else None,
+                        "languages": [
+                            {
+                                "language_code": tl.language_code,
+                                "translated_value": tl.translated_value,
+                                "final_value": tl.final_value or tl.translated_value,
+                                "source_language_detected": tl.source_language_detected,
+                                "status": tl.status,
+                                "needs_review": tl.needs_review or False,
+                            }
+                            for tl in (r.languages or [])
+                        ],
                     }
                     for r in records
                 ],
@@ -995,6 +1008,7 @@ class TranslationOrchestrator:
             "translation_column": job.translation_column,
             "context_columns": job.context_columns,
             "target_language": job.target_language,
+            "target_languages": sorted(job.target_languages) if job.target_languages else [],
             "provider_id": job.provider_id,
             "batch_size": job.batch_size,
             "upsert_strategy": job.upsert_strategy,

backend/src/plugins/translate/service.py

@@ -865,6 +865,7 @@ class BulkFindReplaceService:
         run_id: str,
         pattern: str,
         is_regex: bool,
+        replacement_text: str,
         target_language: str,
     ) -> list[dict]:
         """Scan TranslationLanguage entries and return matching items without applying changes."""
@@ -888,7 +889,7 @@ class BulkFindReplaceService:
                 source_term = record.source_sql if record else ""
 
                 new_value = compiled.sub(
-                    BulkFindReplaceService._get_replacement(pattern, is_regex),
+                    replacement_text,
                     current_value,
                 )
                 if new_value != current_value:
@@ -904,10 +905,9 @@ class BulkFindReplaceService:
         return preview_items
 
     @staticmethod
-    def _get_replacement(pattern: str, is_regex: bool) -> str:
+    def _get_replacement(replacement_text: str, is_regex: bool) -> str:
         """Return replacement pattern (for regex, use backrefs; for plain, use literal)."""
-        # The replacement_text is passed through at apply time
-        return pattern  # Placeholder — actual replacement is done in apply()
+        return replacement_text
 
     @staticmethod
     def apply(