email: per-mailbox captured/matched counts on Email Capture (v0.1.0:65)

/api/email/accounts now returns captured + matched per account (from the per-mailbox
sighting table email_account_messages joined to emails; emails dedupe globally so an
email seen by two mailboxes counts for each). Each mailbox card on the Email Capture
page shows "<N> captured · <M> matched" so per-user coverage is visible, not just the
aggregate. Verified in preview with two seeded mailboxes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/email_integration/routes.py

@@ -162,6 +162,22 @@ def _h_list_accounts(handler):
             "FROM email_accounts ORDER BY email_address"
         )
         rows = [dict(r) for r in cur.fetchall()]
+        # Per-mailbox counts: emails are de-duplicated globally, so "captured per
+        # mailbox" comes from the per-account sighting table; "matched" joins to emails.
+        captured, matched = {}, {}
+        try:
+            captured = {r["account_id"]: r["n"] for r in cur.execute(
+                "SELECT account_id, COUNT(*) AS n FROM email_account_messages "
+                "WHERE deleted_at IS NULL GROUP BY account_id")}
+            matched = {r["account_id"]: r["n"] for r in cur.execute(
+                "SELECT eam.account_id AS account_id, COUNT(*) AS n FROM email_account_messages eam "
+                "JOIN emails e ON e.id = eam.email_id "
+                "WHERE eam.deleted_at IS NULL AND e.is_matched = 1 GROUP BY eam.account_id")}
+        except sqlite3.OperationalError:
+            pass
+        for r in rows:
+            r["captured"] = captured.get(r["id"], 0)
+            r["matched"] = matched.get(r["id"], 0)
     finally:
         conn.close()
     # Non-admins only see their own row