feat: initial implementation of uptodownbot

Telegram bot for downloading media from any site using yt-dlp.
Supports audio/video/both, quality selection, language picker,
container format selection, playlist pagination, progress updates,
per-user quotas, user preferences, download history, cancel at any step,
polling and webhook modes, proxy support, and SQLite persistence.

internal/repo/migrations/001_init.sql

@@ -0,0 +1,51 @@
+-- +goose Up
+CREATE TABLE IF NOT EXISTS users (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    chat_id INTEGER NOT NULL UNIQUE,
+    language TEXT NOT NULL DEFAULT 'en',
+    created_at TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+CREATE TABLE IF NOT EXISTS user_preferences (
+    user_id INTEGER PRIMARY KEY REFERENCES users(id),
+    default_media_type TEXT NOT NULL DEFAULT 'video_audio',
+    default_quality TEXT NOT NULL DEFAULT 'best',
+    default_container TEXT NOT NULL DEFAULT 'mp4',
+    default_language TEXT NOT NULL DEFAULT ''
+);
+
+CREATE TABLE IF NOT EXISTS user_quotas (
+    user_id INTEGER PRIMARY KEY REFERENCES users(id),
+    daily_limit_mb INTEGER NOT NULL DEFAULT 100,
+    daily_used_mb INTEGER NOT NULL DEFAULT 0,
+    daily_date TEXT NOT NULL DEFAULT '',
+    weekly_limit_mb INTEGER NOT NULL DEFAULT 500,
+    weekly_used_mb INTEGER NOT NULL DEFAULT 0,
+    week_start TEXT NOT NULL DEFAULT '',
+    monthly_limit_mb INTEGER NOT NULL DEFAULT 2000,
+    monthly_used_mb INTEGER NOT NULL DEFAULT 0,
+    month_start TEXT NOT NULL DEFAULT '',
+    updated_at TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+CREATE TABLE IF NOT EXISTS download_history (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    user_id INTEGER NOT NULL REFERENCES users(id),
+    url TEXT NOT NULL,
+    title TEXT NOT NULL,
+    media_type TEXT NOT NULL,
+    format_id TEXT NOT NULL,
+    container TEXT NOT NULL,
+    file_size INTEGER NOT NULL DEFAULT 0,
+    status TEXT NOT NULL DEFAULT 'completed',
+    created_at TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+CREATE INDEX IF NOT EXISTS idx_history_user ON download_history(user_id);
+CREATE INDEX IF NOT EXISTS idx_history_user_created ON download_history(user_id, created_at);
+
+-- +goose Down
+DROP TABLE IF EXISTS download_history;
+DROP TABLE IF EXISTS user_quotas;
+DROP TABLE IF EXISTS user_preferences;
+DROP TABLE IF EXISTS users;