chore: sweep dead code across all three services

Per review §1 — verified no callers before each deletion:

- _next_scrape_utc (context dict key never read by any template)
- ALERT_SCRAPE_INTERVAL_SECONDS settings import (only _next_scrape_utc read it)
- alert/paths.py (imported by nothing)
- alert/settings.py LANGUAGE (alert doesn't use translations.toml)
- alert/main.py: the vestigial `c = {}` connectivity dict, the comment
  about re-enabling it, and the entire connectivity block in
  _flat_payload — the web-side columns stay NULL on insert now
- alert/maps.py: DESTINATIONS, calculate_score, _get_next_weekday,
  _calculate_transfers (only geocode is used in the scraper)
- alert/flat.py: connectivity + display_address properties,
  _connectivity field, unused datetime import
- apply/utils.py str_to_preview (no callers) — file removed
- web/matching.py: max_morning_commute + commute check
- web/app.py: don't pass connectivity dict into flat_matches_filter,
  don't write email_address through update_notifications
- web/db.py: get_error (no callers); drop kill_switch,
  max_morning_commute, email_address from their allowed-sets so they're
  not writable through update_* anymore
- web/settings.py + docker-compose.yml: SMTP_HOST/PORT/USERNAME/PASSWORD/
  FROM/STARTTLS (notifications.py is telegram-only now)

DB columns themselves (kill_switch, email_address, max_morning_commute,
connectivity_morning_time, connectivity_night_time) stay in the schema
— SQLite can't drop them cheaply and they're harmless.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

alert/maps.py

@@ -1,25 +1,12 @@
 import logging
 
 import googlemaps
-from datetime import datetime, timedelta, time as dt_time
 from settings import GMAPS_API_KEY
 
 logger = logging.getLogger("flat-alert")
 
-class Maps:
-    DESTINATIONS = {
-        "Hbf": "Berlin Hauptbahnhof",
-        "Friedrichstr": "Friedrichstraße, Berlin",
-        "Kotti": "Kottbusser Tor, Berlin",
-        "Warschauer": "Warschauer Straße, Berlin",
-        "Ostkreuz": "Ostkreuz, Berlin",
-        "Nollendorf": "Nollendorfplatz, Berlin",
-        "Zoo": "Zoologischer Garten, Berlin",
-        "Kudamm": "Kurfürstendamm, Berlin",
-        "Gesundbrunnen": "Gesundbrunnen, Berlin",
-        "Hermannplatz": "Hermannplatz, Berlin"
-    }
 
+class Maps:
     def __init__(self):
         self.gmaps = googlemaps.Client(key=GMAPS_API_KEY)
 
@@ -36,69 +23,3 @@ class Maps:
         except Exception as e:
             logger.warning("geocode failed for %r: %s", address, e)
             return None
-
-    def _get_next_weekday(self, date, weekday):
-        days_ahead = weekday - date.weekday()
-        if days_ahead <= 0:
-            days_ahead += 7
-        return date + timedelta(days_ahead)
-
-    def _calculate_transfers(self, steps):
-        transit_count = sum(1 for step in steps if step['travel_mode'] == 'TRANSIT')
-        return max(0, transit_count - 1)
-
-    def calculate_score(self, origin_address):
-        now = datetime.now()
-        # Next Monday 8:00 AM
-        next_monday = self._get_next_weekday(now, 0)
-        morning_departure = datetime.combine(next_monday.date(), dt_time(8, 0))
-        # Next Sunday 2:00 AM
-        next_sunday = self._get_next_weekday(now, 6)
-        night_departure = datetime.combine(next_sunday.date(), dt_time(2, 0))
-
-        total_morning_minutes = 0
-        total_morning_transfers = 0
-        total_night_minutes = 0
-        total_night_transfers = 0
-        dest_count = 0
-
-        for key, dest_address in self.DESTINATIONS.items():
-            # Morning: Flat -> Center
-            routes_morning = self.gmaps.directions(
-                origin=origin_address,
-                destination=dest_address,
-                mode="transit",
-                departure_time=morning_departure
-            )
-
-            # Night: Center -> Flat
-            routes_night = self.gmaps.directions(
-                origin=dest_address,
-                destination=origin_address,
-                mode="transit",
-                departure_time=night_departure
-            )
-
-            if routes_morning:
-                leg = routes_morning[0]['legs'][0]
-                total_morning_minutes += leg['duration']['value'] / 60
-                total_morning_transfers += self._calculate_transfers(leg['steps'])
-
-            if routes_night:
-                leg = routes_night[0]['legs'][0]
-                total_night_minutes += leg['duration']['value'] / 60
-                total_night_transfers += self._calculate_transfers(leg['steps'])
-
-            dest_count += 1
-
-        avg_m_time = total_morning_minutes / dest_count if dest_count else 0
-        avg_m_trans = total_morning_transfers / dest_count if dest_count else 0
-        avg_n_time = total_night_minutes / dest_count if dest_count else 0
-        avg_n_trans = total_night_transfers / dest_count if dest_count else 0
-
-        return {
-            'morning_time': avg_m_time,
-            'morning_transfers': avg_m_trans,
-            'night_time': avg_n_time,
-            'night_transfers': avg_n_trans
-        }