feat(insta-lab): db migration — trending_keywords.source + account_preferences + CRUD

- Idempotent ALTER TABLE adds source column (default 'manual') + idx_tk_source index
- New account_preferences table seeded with economy/psychology/celebrity at weight=1.0
- add_trending_keyword now accepts optional source param
- New helpers: add_external_trend, list_trends, get_preferences, upsert_preferences
- test_db updated: six→seven tables; test_preferences_crud.py (7 new tests, all pass)

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

insta-lab/app/db.py

@@ -101,6 +101,29 @@ def init_db() -> None:
             )
         """)
 
+        # source column for trending_keywords (idempotent ALTER)
+        cols = [r[1] for r in conn.execute("PRAGMA table_info(trending_keywords)").fetchall()]
+        if "source" not in cols:
+            conn.execute("ALTER TABLE trending_keywords ADD COLUMN source TEXT NOT NULL DEFAULT 'manual'")
+            conn.execute("CREATE INDEX IF NOT EXISTS idx_tk_source ON trending_keywords(source, suggested_at DESC)")
+
+        # account_preferences — 카테고리 가중치
+        conn.execute("""
+            CREATE TABLE IF NOT EXISTS account_preferences (
+                category    TEXT PRIMARY KEY,
+                weight      REAL NOT NULL DEFAULT 1.0,
+                updated_at  TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ','now'))
+            )
+        """)
+        # seed defaults if table empty
+        existing = conn.execute("SELECT COUNT(*) FROM account_preferences").fetchone()[0]
+        if existing == 0:
+            for cat in ("economy", "psychology", "celebrity"):
+                conn.execute(
+                    "INSERT INTO account_preferences(category, weight) VALUES(?,?)",
+                    (cat, 1.0),
+                )
+
 
 # ── news_articles ────────────────────────────────────────────────
 def add_news_article(row: Dict[str, Any]) -> int:
@@ -132,8 +155,12 @@ def list_news_articles(category: Optional[str] = None, days: int = 1) -> List[Di
 def add_trending_keyword(row: Dict[str, Any]) -> int:
     with _conn() as conn:
         cur = conn.execute(
-            "INSERT INTO trending_keywords(keyword, category, score, articles_count) VALUES(?,?,?,?)",
-            (row["keyword"], row["category"], float(row.get("score", 0.0)), int(row.get("articles_count", 0))),
+            "INSERT INTO trending_keywords(keyword, category, score, articles_count, source) VALUES(?,?,?,?,?)",
+            (
+                row["keyword"], row["category"],
+                float(row.get("score", 0.0)), int(row.get("articles_count", 0)),
+                row.get("source", "manual"),
+            ),
         )
         return cur.lastrowid
 
@@ -276,3 +303,50 @@ def get_prompt_template(name: str) -> Optional[Dict[str, Any]]:
     with _conn() as conn:
         row = conn.execute("SELECT * FROM prompt_templates WHERE name=?", (name,)).fetchone()
     return dict(row) if row else None
+
+
+# ── external trends ─────────────────────────────────────────────
+def add_external_trend(row: Dict[str, Any]) -> int:
+    """`source` 필수 — naver_popular | google_trends. trending_keywords에 인서트."""
+    if "source" not in row:
+        raise ValueError("add_external_trend requires 'source' field")
+    return add_trending_keyword(row)
+
+
+def list_trends(source: Optional[str] = None, category: Optional[str] = None,
+                days: int = 1) -> List[Dict[str, Any]]:
+    sql = "SELECT * FROM trending_keywords WHERE suggested_at >= datetime('now', ?)"
+    params: List[Any] = [f"-{int(days)} days"]
+    if source and source != "all":
+        sql += " AND source=?"
+        params.append(source)
+    if category:
+        sql += " AND category=?"
+        params.append(category)
+    sql += " ORDER BY suggested_at DESC, score DESC"
+    with _conn() as conn:
+        rows = conn.execute(sql, params).fetchall()
+    return [dict(r) for r in rows]
+
+
+# ── account_preferences ─────────────────────────────────────────
+def get_preferences() -> List[Dict[str, Any]]:
+    with _conn() as conn:
+        rows = conn.execute(
+            "SELECT category, weight, updated_at FROM account_preferences ORDER BY category ASC"
+        ).fetchall()
+    return [dict(r) for r in rows]
+
+
+def upsert_preferences(weights: Dict[str, float]) -> None:
+    """전체 upsert. 기존에 있던 카테고리는 weight 갱신, 신규는 INSERT.
+    명시되지 않은 기존 카테고리는 그대로 둔다 (삭제 X). 삭제 필요 시 별도 API로."""
+    with _conn() as conn:
+        for cat, w in weights.items():
+            conn.execute("""
+                INSERT INTO account_preferences(category, weight)
+                     VALUES(?,?)
+                ON CONFLICT(category) DO UPDATE SET
+                    weight=excluded.weight,
+                    updated_at=strftime('%Y-%m-%dT%H:%M:%fZ','now')
+            """, (cat, float(w)))