db: add schema for API keys, audit log, and per-minute uptime; migrate links/clicks

New tables: api_keys (hashed bearer tokens with scopes), audit_log (admin
action trail), uptime_minutes (multi-worker-safe availability marks).
Idempotent column migrations: links.redirect_type (default 302),
links.password_hash, links.deleted_at, clicks.is_bot. Existing databases
upgrade in place on next startup.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app.py

@@ -134,6 +134,28 @@ def init_db():
                 checks_total INTEGER DEFAULT 0,
                 checks_up    INTEGER DEFAULT 0
             );
+            CREATE TABLE IF NOT EXISTS uptime_minutes (
+                minute TEXT PRIMARY KEY
+            );
+            CREATE TABLE IF NOT EXISTS api_keys (
+                id           INTEGER PRIMARY KEY AUTOINCREMENT,
+                user_id      INTEGER NOT NULL REFERENCES users(id),
+                name         TEXT NOT NULL,
+                key_hash     TEXT UNIQUE NOT NULL,
+                prefix       TEXT NOT NULL,
+                scope        TEXT NOT NULL DEFAULT 'read',
+                created_at   TEXT NOT NULL,
+                last_used_at TEXT,
+                revoked      INTEGER DEFAULT 0
+            );
+            CREATE TABLE IF NOT EXISTS audit_log (
+                id         INTEGER PRIMARY KEY AUTOINCREMENT,
+                actor      TEXT,
+                action     TEXT NOT NULL,
+                target     TEXT,
+                details    TEXT,
+                created_at TEXT NOT NULL
+            );
             CREATE INDEX IF NOT EXISTS idx_links_code  ON links(code);
             CREATE INDEX IF NOT EXISTS idx_clicks_link ON clicks(link_id);
             CREATE INDEX IF NOT EXISTS idx_clicks_at   ON clicks(clicked_at);
@@ -146,6 +168,10 @@ def init_db():
             "ALTER TABLE clicks ADD COLUMN country TEXT",
             "ALTER TABLE users ADD COLUMN plan TEXT NOT NULL DEFAULT 'free'",
             "ALTER TABLE users ADD COLUMN org_id INTEGER REFERENCES organizations(id)",
+            "ALTER TABLE links ADD COLUMN redirect_type INTEGER DEFAULT 302",
+            "ALTER TABLE links ADD COLUMN password_hash TEXT",
+            "ALTER TABLE links ADD COLUMN deleted_at TEXT",
+            "ALTER TABLE clicks ADD COLUMN is_bot INTEGER DEFAULT 0",
         ]:
             try:
                 conn.execute(migration)