chore: init monorepo with GPL-3.0 license, docs, backend skeleton, frontend wiring

indexium-backend/migrations/20260907000000_telemetry.sql

@@ -0,0 +1,30 @@
+-- Indexium Analytics: bStats аналог
+
+CREATE TABLE IF NOT EXISTS mod_telemetry_pings (
+    id BIGSERIAL PRIMARY KEY,
+    mod_id UUID NOT NULL REFERENCES mods(id) ON DELETE CASCADE,
+    server_hash CHAR(64) NOT NULL,
+    mc_version VARCHAR(16) NOT NULL,
+    loader VARCHAR(16) NOT NULL,
+    os VARCHAR(16) NOT NULL,
+    java_version VARCHAR(16) NOT NULL,
+    player_count INT NOT NULL DEFAULT 0,
+    pinged_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_telemetry_lookup ON mod_telemetry_pings (mod_id, pinged_at DESC);
+CREATE INDEX IF NOT EXISTS idx_telemetry_hash ON mod_telemetry_pings (server_hash, pinged_at);
+
+CREATE TABLE IF NOT EXISTS mod_daily_stats (
+    mod_id UUID NOT NULL REFERENCES mods(id) ON DELETE CASCADE,
+    date DATE NOT NULL,
+    active_servers INT NOT NULL DEFAULT 0,
+    active_players INT NOT NULL DEFAULT 0,
+    breakdown_json JSONB NOT NULL,
+    PRIMARY KEY (mod_id, date)
+);
+
+CREATE TABLE IF NOT EXISTS analytics_salts (
+    date DATE PRIMARY KEY,
+    salt CHAR(64) NOT NULL
+);