feat: house tracker with home worker, alerts and listing map

Collects Pararius rent/buy listings into Postgres via a worker that runs on a
residential connection, sends Discord/ntfy alerts for new listings matching
rules, and shows an admin-only map, market stats and worker log.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013HfF5tnChi8tkCx9svJP6D

scripts/house-tracker-migration.sql

@@ -0,0 +1,111 @@
+-- House tracker: listings from Dutch housing sites, collected by a home worker.
+-- Idempotent; safe to run on every deploy.
+
+CREATE TABLE IF NOT EXISTS house_listings (
+  id serial PRIMARY KEY,
+  source text NOT NULL,
+  source_id text NOT NULL,
+  external_id text,
+  url text NOT NULL,
+  offer text NOT NULL CHECK (offer IN ('rent', 'buy')),
+  property_type text NOT NULL,
+  title text,
+  street text,
+  postal_code text,
+  city text,
+  city_slug text,
+  neighbourhood text,
+  price_eur integer CHECK (price_eur IS NULL OR price_eur >= 0),
+  area_m2 integer,
+  rooms integer,
+  bedrooms integer,
+  bathrooms integer,
+  construction_year integer,
+  energy_label text,
+  interior text,
+  deposit_eur integer,
+  available_from text,
+  contract_type text,
+  agent text,
+  image_url text,
+  description text,
+  features jsonb NOT NULL DEFAULT '{}'::jsonb,
+  lat double precision,
+  lng double precision,
+  -- When the site says it was published. first_seen_at is when we noticed.
+  offered_at timestamptz,
+  first_seen_at timestamptz NOT NULL DEFAULT now(),
+  -- fast, slow, or seed (already listed when its search was first polled).
+  first_seen_lane text NOT NULL DEFAULT 'slow',
+  last_seen_at timestamptz NOT NULL DEFAULT now(),
+  detail_fetched_at timestamptz,
+  removed_at timestamptz,
+  alerted_at timestamptz,
+  -- Personal tracking.
+  status text,
+  notes text
+);
+CREATE UNIQUE INDEX IF NOT EXISTS house_listings_source_idx ON house_listings (source, source_id);
+CREATE INDEX IF NOT EXISTS house_listings_active_idx
+  ON house_listings (offer, first_seen_at DESC) WHERE removed_at IS NULL;
+CREATE INDEX IF NOT EXISTS house_listings_city_idx ON house_listings (source, offer, city_slug);
+CREATE INDEX IF NOT EXISTS house_listings_details_idx
+  ON house_listings (first_seen_at DESC) WHERE detail_fetched_at IS NULL;
+
+-- Every price we have seen, so price drops and market trends survive edits.
+CREATE TABLE IF NOT EXISTS house_price_history (
+  listing_id integer NOT NULL REFERENCES house_listings(id) ON DELETE CASCADE,
+  observed_at timestamptz NOT NULL DEFAULT now(),
+  price_eur integer NOT NULL
+);
+CREATE INDEX IF NOT EXISTS house_price_history_listing_idx
+  ON house_price_history (listing_id, observed_at);
+
+-- One row per polled search URL. The first sync of a search only seeds the
+-- database: alerting on everything already listed would be noise.
+CREATE TABLE IF NOT EXISTS house_searches (
+  search_url text PRIMARY KEY,
+  source text NOT NULL,
+  lane text NOT NULL,
+  first_synced_at timestamptz NOT NULL DEFAULT now(),
+  last_synced_at timestamptz NOT NULL DEFAULT now(),
+  last_found integer NOT NULL DEFAULT 0
+);
+
+-- Worker health: challenges, HTTP errors, parse failures.
+CREATE TABLE IF NOT EXISTS house_worker_runs (
+  id bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
+  source text NOT NULL,
+  lane text NOT NULL,
+  url text NOT NULL,
+  status text NOT NULL,
+  http_status integer,
+  found integer,
+  duration_ms integer,
+  message text,
+  created_at timestamptz NOT NULL DEFAULT now()
+);
+CREATE INDEX IF NOT EXISTS house_worker_runs_created_idx ON house_worker_runs (created_at DESC);
+
+CREATE TABLE IF NOT EXISTS house_alert_rules (
+  id serial PRIMARY KEY,
+  name text NOT NULL,
+  enabled boolean NOT NULL DEFAULT true,
+  offer text NOT NULL DEFAULT 'rent' CHECK (offer IN ('rent', 'buy')),
+  min_price integer,
+  max_price integer,
+  min_area integer,
+  min_bedrooms integer,
+  -- Lowercase city names; empty means anywhere.
+  cities text[] NOT NULL DEFAULT '{}',
+  -- Empty means every property type.
+  property_types text[] NOT NULL DEFAULT '{}',
+  created_at timestamptz NOT NULL DEFAULT now()
+);
+
+INSERT INTO house_alert_rules (name, offer, min_price, max_price, cities)
+SELECT 'Gouda area rentals', 'rent', 1300, 1700, ARRAY[
+  'gouda', 'waddinxveen', 'reeuwijk', 'moordrecht', 'nieuwerkerk aan den ijssel',
+  'zevenhuizen', 'bodegraven', 'boskoop', 'oudewater', 'schoonhoven', 'haastrecht'
+]
+WHERE NOT EXISTS (SELECT 1 FROM house_alert_rules);