Add Rate Monitor app — Booking.com + direct booking engine competitor rates

Combines Booking.com Playwright scraper (from forecasting), direct booking
engine scraper (ported from laptop-archive/guestline-monitor), and Newbook
own-hotel rates into one focused tool. Four views: Bookability, Market View
(with price index badges + direct rate sub-rows), Direct Rates (per-competitor
room breakdown, min-stay flags, hotel config/discovery), Rate Analysis
(advance purchase curve, DOW chart, rate timeline, comparison table).

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

backend/services/direct_profiles/base.py

@@ -0,0 +1,25 @@
+from abc import ABC, abstractmethod
+
+
+class BaseProfile(ABC):
+    name: str = ""
+    label: str = ""
+    # Fields required to configure this engine, shown in the add-hotel form
+    # Each entry: {"key": "hotel_id", "label": "Hotel ID", "help": "e.g. THREEWAYS"}
+    required_params: list[dict] = []
+
+    @classmethod
+    @abstractmethod
+    def detect(cls, url: str) -> dict | None:
+        """Return extracted params dict if URL matches this engine, else None."""
+
+    @abstractmethod
+    async def fetch_arrival_dates(self, client, params: dict) -> list[str]:
+        """Return list of bookable arrival date strings YYYY-MM-DD."""
+
+    @abstractmethod
+    async def fetch_night_rates(self, client, params: dict, arrival: str, nights: int = 1) -> list[dict]:
+        """Return list of room/rate dicts for the stay.
+        Each dict must have: roomId, rateId, availability, prices[{amountBeforeTax, amountAfterTax}], currencyCode
+        prices list has one entry per night when nights > 1.
+        """