feat(tasks): Add proxy_test task handler and discovery run tracking

- Add proxy_test task handler that fetches IP via proxy to verify connectivity
- Add discovery_runs migration (083) for tracking store discovery progress
- Register proxy_test in task service and worker

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/migrations/083_discovery_runs.sql

@@ -0,0 +1,88 @@
+-- Migration 083: Discovery Run Tracking
+-- Tracks progress of store discovery runs step-by-step
+
+-- Main discovery runs table
+CREATE TABLE IF NOT EXISTS discovery_runs (
+  id SERIAL PRIMARY KEY,
+  platform VARCHAR(50) NOT NULL DEFAULT 'dutchie',
+  status VARCHAR(20) NOT NULL DEFAULT 'running', -- running, completed, failed
+  started_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  finished_at TIMESTAMPTZ,
+  task_id INTEGER REFERENCES worker_task_queue(id),
+
+  -- Totals
+  states_total INTEGER DEFAULT 0,
+  states_completed INTEGER DEFAULT 0,
+  locations_discovered INTEGER DEFAULT 0,
+  locations_promoted INTEGER DEFAULT 0,
+  new_store_ids INTEGER[] DEFAULT '{}',
+
+  -- Error info
+  error_message TEXT,
+
+  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- Per-state progress within a run
+CREATE TABLE IF NOT EXISTS discovery_run_states (
+  id SERIAL PRIMARY KEY,
+  run_id INTEGER NOT NULL REFERENCES discovery_runs(id) ON DELETE CASCADE,
+  state_code VARCHAR(2) NOT NULL,
+  status VARCHAR(20) NOT NULL DEFAULT 'pending', -- pending, running, completed, failed
+  started_at TIMESTAMPTZ,
+  finished_at TIMESTAMPTZ,
+
+  -- Results
+  cities_found INTEGER DEFAULT 0,
+  locations_found INTEGER DEFAULT 0,
+  locations_upserted INTEGER DEFAULT 0,
+  new_dispensary_ids INTEGER[] DEFAULT '{}',
+
+  -- Error info
+  error_message TEXT,
+
+  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+
+  UNIQUE(run_id, state_code)
+);
+
+-- Step-by-step log for detailed progress tracking
+CREATE TABLE IF NOT EXISTS discovery_run_steps (
+  id SERIAL PRIMARY KEY,
+  run_id INTEGER NOT NULL REFERENCES discovery_runs(id) ON DELETE CASCADE,
+  state_code VARCHAR(2),
+  step_name VARCHAR(100) NOT NULL,
+  status VARCHAR(20) NOT NULL DEFAULT 'started', -- started, completed, failed
+  started_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  finished_at TIMESTAMPTZ,
+
+  -- Details (JSON for flexibility)
+  details JSONB DEFAULT '{}',
+
+  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- Indexes for querying
+CREATE INDEX IF NOT EXISTS idx_discovery_runs_status ON discovery_runs(status);
+CREATE INDEX IF NOT EXISTS idx_discovery_runs_platform ON discovery_runs(platform);
+CREATE INDEX IF NOT EXISTS idx_discovery_runs_started_at ON discovery_runs(started_at DESC);
+CREATE INDEX IF NOT EXISTS idx_discovery_run_states_run_id ON discovery_run_states(run_id);
+CREATE INDEX IF NOT EXISTS idx_discovery_run_steps_run_id ON discovery_run_steps(run_id);
+
+-- View for latest run status per platform
+CREATE OR REPLACE VIEW v_latest_discovery_runs AS
+SELECT DISTINCT ON (platform)
+  id,
+  platform,
+  status,
+  started_at,
+  finished_at,
+  states_total,
+  states_completed,
+  locations_discovered,
+  locations_promoted,
+  array_length(new_store_ids, 1) as new_stores_count,
+  error_message,
+  EXTRACT(EPOCH FROM (COALESCE(finished_at, NOW()) - started_at)) as duration_seconds
+FROM discovery_runs
+ORDER BY platform, started_at DESC;