feat(realestate-db): add district / notify / 5tier columns with migration

- announcements.district + idx_ann_district 인덱스
- user_profile: preferred_districts(JSON obj), min_match_score(int 70), notify_enabled(bool)
- match_results: notified_at(TEXT)
- _profile_row_to_dict: notify_enabled bool화, preferred_districts dict 역직렬화
- PROFILE_COLUMNS 확장 (3 신규 필드)
- upsert_profile: list|dict 모두 JSON 직렬화

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

realestate-lab/app/db.py

@@ -64,6 +64,13 @@ def init_db():
         conn.execute("CREATE INDEX IF NOT EXISTS idx_ann_status ON announcements(status);")
         conn.execute("CREATE INDEX IF NOT EXISTS idx_ann_region ON announcements(region_name);")
 
+        # ── 마이그레이션: district 컬럼 + 인덱스 추가 ──
+        try:
+            conn.execute("SELECT district FROM announcements LIMIT 1")
+        except Exception:
+            conn.execute("ALTER TABLE announcements ADD COLUMN district TEXT")
+        conn.execute("CREATE INDEX IF NOT EXISTS idx_ann_district ON announcements(district);")
+
         # ── 마이그레이션: is_bookmarked 컬럼 추가 ──
         try:
             conn.execute("SELECT is_bookmarked FROM announcements LIMIT 1")
@@ -120,6 +127,17 @@ def init_db():
             );
         """)
 
+        # ── 마이그레이션: user_profile 신규 3컬럼 ──
+        for col, ddl in (
+            ("preferred_districts", "ALTER TABLE user_profile ADD COLUMN preferred_districts TEXT NOT NULL DEFAULT '{}'"),
+            ("min_match_score",    "ALTER TABLE user_profile ADD COLUMN min_match_score INTEGER NOT NULL DEFAULT 70"),
+            ("notify_enabled",     "ALTER TABLE user_profile ADD COLUMN notify_enabled INTEGER NOT NULL DEFAULT 1"),
+        ):
+            try:
+                conn.execute(f"SELECT {col} FROM user_profile LIMIT 1")
+            except Exception:
+                conn.execute(ddl)
+
         # ── match_results ────────────────────────────────────────────────
         conn.execute("""
             CREATE TABLE IF NOT EXISTS match_results (
@@ -135,6 +153,12 @@ def init_db():
             );
         """)
 
+        # ── 마이그레이션: notified_at 컬럼 추가 ──
+        try:
+            conn.execute("SELECT notified_at FROM match_results LIMIT 1")
+        except Exception:
+            conn.execute("ALTER TABLE match_results ADD COLUMN notified_at TEXT")
+
         # ── collect_log ──────────────────────────────────────────────────
         conn.execute("""
             CREATE TABLE IF NOT EXISTS collect_log (
@@ -539,10 +563,12 @@ def _profile_row_to_dict(r) -> Dict[str, Any]:
     for c in r.keys():
         val = r[c]
         if c in ("is_homeless", "is_householder", "has_dependents", "is_newlywed",
-                  "has_newborn", "is_first_home"):
+                  "has_newborn", "is_first_home", "notify_enabled"):
             d[c] = bool(val) if val is not None else None
         elif c in ("preferred_regions", "preferred_types"):
             d[c] = json.loads(val) if val else []
+        elif c == "preferred_districts":
+            d[c] = json.loads(val) if val else {}
         else:
             d[c] = val
     return d
@@ -563,8 +589,9 @@ PROFILE_COLUMNS = {
     "subscription_months", "subscription_amount", "family_members",
     "has_dependents", "children_count", "is_newlywed", "marriage_months",
     "has_newborn", "is_first_home", "income_level",
-    "preferred_regions", "preferred_types",
+    "preferred_regions", "preferred_types", "preferred_districts",
     "min_area", "max_area", "max_price",
+    "min_match_score", "notify_enabled",
 }
 
 
@@ -575,7 +602,7 @@ def upsert_profile(data: Dict[str, Any]) -> Dict[str, Any]:
             continue
         if isinstance(v, bool):
             updates[k] = 1 if v else 0
-        elif isinstance(v, list):
+        elif isinstance(v, (list, dict)):
             updates[k] = json.dumps(v)
         else:
             updates[k] = v