Initial scaffold: Go module, SQLite schema, config loader, Telegram bot with webhook/polling modes

db/schema.sql

@@ -0,0 +1,26 @@
+CREATE TABLE events (
+    id INTEGER PRIMARY KEY,
+    event_type TEXT NOT NULL
+        CHECK (event_type IN ('in', 'out')),
+    occurred_at INTEGER NOT NULL UNIQUE
+          CHECK (occurred_at > 0),
+      note TEXT NOT NULL DEFAULT '',
+    created_at INTEGER NOT NULL
+          DEFAULT (unixepoch())
+);
+
+CREATE INDEX idx_events_occurred_at
+ON events(occurred_at);
+
+CREATE TABLE IF NOT EXISTS settings (
+    key   TEXT PRIMARY KEY,
+    value TEXT NOT NULL DEFAULT ''
+);
+
+CREATE TABLE days_off (
+    date TEXT PRIMARY KEY
+          CHECK (date = strftime('%Y-%m-%d', date)),
+    reason TEXT NOT NULL DEFAULT '',
+    created_at INTEGER NOT NULL
+          DEFAULT (unixepoch())
+);