feat(mapari): regula 'exclude de la declarare' per operatie + stare preview Nedeclarat

Operatiile care nu se declara la RAR (ex. ITP facturat in service) primesc o
regula exclus=1 in operations_mapping, setabila din panoul de mapare al
preview-ului de import si din tab-ul Mapari (optiunea 'Nu se declara la RAR').

- resolve_prestatii(excluded_ops): item nemapat cu op exclusa -> adnotat exclus,
  nu mai e needs_mapping; precedenta: cod explicit > exclus > mapare > reguli text
- split_prestatii_excluse: itemii exclusi nu intra niciodata in payload/cheie
- preview import: rand cu toate operatiile excluse -> stare 'excluded'
  (eticheta Nedeclarat), necomis; operatia dispare din panoul de mapat
- reresolve/corectie/API: submission cu toate operatiile excluse -> needs_data
  cu motiv explicit; ingestia API trateaza excluderea la clasificare
- migrare: coloana operations_mapping.exclus + rebuild import_rows pentru
  CHECK-ul resolved_status cu 'excluded' (o singura data, gardat pe sqlite_master)
- fix flake: clamp similaritate embeddings la [-1,1] (float32 dadea 1.0000001)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/db.py

@@ -178,6 +178,26 @@ def _migrate(conn: sqlite3.Connection) -> None:
             conn.execute(
                 "ALTER TABLE import_rows ADD COLUMN reviewed INTEGER NOT NULL DEFAULT 0"
             )
+        # CHECK-ul resolved_status trebuie sa accepte 'excluded' (operatii excluse de la
+        # declarare). SQLite nu poate altera CHECK -> rebuild o singura data (detectat
+        # pe textul CREATE din sqlite_master).
+        create_sql = str(conn.execute(
+            "SELECT sql FROM sqlite_master WHERE type='table' AND name='import_rows'"
+        ).fetchone()["sql"] or "")
+        if "'excluded'" not in create_sql:
+            _rebuild_import_rows_cu_excluded(conn)
+
+    # Coloana operations_mapping.exclus: regula "nu se declara la RAR" per operatie.
+    om_tbl = conn.execute(
+        "SELECT name FROM sqlite_master WHERE type='table' AND name='operations_mapping'"
+    ).fetchone()
+    if om_tbl:
+        om_cols = {r["name"] for r in conn.execute("PRAGMA table_info(operations_mapping)").fetchall()}
+        if "exclus" not in om_cols:
+            conn.execute(
+                "ALTER TABLE operations_mapping ADD COLUMN exclus INTEGER NOT NULL DEFAULT 0 "
+                "CHECK (exclus IN (0, 1))"
+            )
 
     # Index batch_id pe submissions (poate lipsi pe DB veche)
     existing_idx = {r["name"] for r in conn.execute(
@@ -201,6 +221,45 @@ def _migrate(conn: sqlite3.Connection) -> None:
         )
 
 
+def _rebuild_import_rows_cu_excluded(conn: sqlite3.Connection) -> None:
+    """Rebuild import_rows cu 'excluded' in CHECK-ul resolved_status.
+
+    Ruleaza O SINGURA DATA pe DB-uri create inainte de starea 'excluded' (gardat de
+    apelant pe textul CREATE). Copiaza toate randurile 1:1 si recreeaza indexul.
+    """
+    conn.execute("BEGIN IMMEDIATE")
+    try:
+        conn.execute(
+            "CREATE TABLE import_rows_new ("
+            " id INTEGER PRIMARY KEY AUTOINCREMENT,"
+            " batch_id INTEGER NOT NULL REFERENCES import_batches(id) ON DELETE CASCADE,"
+            " row_index INTEGER NOT NULL,"
+            " raw_json TEXT NOT NULL,"
+            " override_json TEXT,"
+            " reviewed INTEGER NOT NULL DEFAULT 0,"
+            " resolved_status TEXT NOT NULL DEFAULT 'pending'"
+            "   CHECK (resolved_status IN ("
+            "     'pending','ok','needs_mapping','needs_data',"
+            "     'needs_review','already_sent','duplicate_in_file','excluded'"
+            "   )),"
+            " error TEXT"
+            ")"
+        )
+        conn.execute(
+            "INSERT INTO import_rows_new "
+            " (id, batch_id, row_index, raw_json, override_json, reviewed, resolved_status, error) "
+            "SELECT id, batch_id, row_index, raw_json, override_json, reviewed, resolved_status, error "
+            "FROM import_rows"
+        )
+        conn.execute("DROP TABLE import_rows")
+        conn.execute("ALTER TABLE import_rows_new RENAME TO import_rows")
+        conn.execute("CREATE INDEX IF NOT EXISTS idx_import_rows_batch ON import_rows(batch_id)")
+        conn.execute("COMMIT")
+    except Exception:
+        conn.execute("ROLLBACK")
+        raise
+
+
 def _migrate_accounts_medii(conn: sqlite3.Connection, acc_cols: set[str]) -> None:
     """Coloane medii RAR per cont + backfill din ancora globala.