Email improvements: domain-aware portal URL, embedded logo, fix product list color

- Store request origin domain in PendingAccessRequest.portal_url
- Use per-request portal URL in approval/rejection emails
- Embed logo as base64 so it displays without external image loading
- Fix 'Предоставлен доступ к продуктам' text color to match body color
- Switch Telegram polling to 30-second interval with single-worker flock fix

app/models.py

@@ -127,5 +127,6 @@ class PendingAccessRequest(Base):
     phone: Mapped[str] = mapped_column(String(64))
     manager: Mapped[str] = mapped_column(String(256), default="")
     products_json: Mapped[str] = mapped_column(Text, default="[]")
+    portal_url: Mapped[str] = mapped_column(String(256), default="")
     status: Mapped[str] = mapped_column(String(16), default="pending")
     created_at: Mapped[dt.datetime] = mapped_column(DateTime(timezone=True), default=lambda: dt.datetime.now(dt.timezone.utc))

app/runtime.py

@@ -808,6 +808,7 @@ def ensure_schema_compatibility() -> None:
         conn.execute(text("ALTER TABLE services ADD COLUMN IF NOT EXISTS svc_password VARCHAR(256) NOT NULL DEFAULT ''"))
         conn.execute(text("ALTER TABLE services ADD COLUMN IF NOT EXISTS svc_cred_hint TEXT NOT NULL DEFAULT ''"))
         conn.execute(text("ALTER TABLE services ADD COLUMN IF NOT EXISTS icon_path TEXT NOT NULL DEFAULT ''"))
+        conn.execute(text("ALTER TABLE pending_access_requests ADD COLUMN IF NOT EXISTS portal_url VARCHAR(256) NOT NULL DEFAULT ''"))
         conn.execute(
             text(
                 """