feat(web): editare celule in preview + Acasa unificata (PRD 3.6)

Implementeaza PRD 3.6 (US-001..007), pe canalul de import + stratul web;
worker / masina stari / idempotenta / mapare raman neatinse.

- US-003/004: tab-ul "Trimiteri" eliminat; Trimiterile devin sectiune
  permanenta sub upload pe Acasa ("Trimiterile tale"); upload comprimat la
  bara slim (hero pastrat la first-run); ?tab=coada si /_fragments/coada
  servesc Acasa (fara fragment orfan); poll gated pe visibilityState.
- US-001: coloana noua import_rows.override_json (nullable, Fernet, Approach B)
  + _migrate defensiv; ruta v1 + alias web .../rand/{i}/editeaza aplica patch
  canonic ULTIMUL in _resolve_row_for_preview si commit_import (mutatie pura,
  status rederivat, fara drift). Scoping JOIN -> 404, guard committed -> 409,
  semantica empty=clear, decrypt fail -> no-op.
- US-002: buton "Editeaza" pe rand; swap pe <tr> + OOB contoare (nu pe sectiune);
  form propriu (confirm dezactivat la editare); refoloseste grila responsiva +
  error-map din _trimitere_detaliu.html; mutual-exclusion intre randuri.
- US-005/006: "De rezolvat", "Operatii salvate" si "Formate de coloane" ca
  tabele (.tablewrap); H4: comutatorul reflecta auto_send STOCAT.
- US-007: bifa "auto-send" devine comutator etichetat pe COADA ("Pune automat
  in coada" / "Tine pentru verificare"), scoped pe operatie; name="auto_send"
  pastrat (semantica de prezenta -> bool corect cu ambele parsere, zero backend).

Fix-uri gasite la verificarea E2E in browser (htmx 1.9.12, JS — invizibile la
TestClient): useTemplateFragments=true (raspuns <tr>+OOB era parsat in context
de tabel -> swapError + contoare pierdute); re-activarea confirm-btn dupa salvare
deferita pe tick (evita editing=true tranzitoriu); n-hint actualizat de updateN.

Teste: 523 passed. E2E browser: Acasa unificata, upload slim, editare rand
(needs_data -> ok, swap pe rand, contoare OOB), Mapari tabelar + comutator.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/db.py

@@ -79,6 +79,17 @@ def _migrate(conn: sqlite3.Connection) -> None:
         if "email_verified" not in user_cols:
             conn.execute("ALTER TABLE users ADD COLUMN email_verified INTEGER NOT NULL DEFAULT 0")
 
+    # Coloana import_rows.override_json (3.6, Approach B): patch canonic editat in
+    # preview, criptat Fernet. Defensiv idempotent (ca is_admin in 3.3b) — DB create
+    # inainte de 3.6 nu au coloana.
+    irows_tbl = conn.execute(
+        "SELECT name FROM sqlite_master WHERE type='table' AND name='import_rows'"
+    ).fetchone()
+    if irows_tbl:
+        irows_cols = {r["name"] for r in conn.execute("PRAGMA table_info(import_rows)").fetchall()}
+        if "override_json" not in irows_cols:
+            conn.execute("ALTER TABLE import_rows ADD COLUMN override_json TEXT")
+
     # Index batch_id pe submissions (poate lipsi pe DB veche)
     existing_idx = {r["name"] for r in conn.execute(
         "SELECT name FROM sqlite_master WHERE type='index' AND tbl_name='submissions'"