Adds src/constants.ts exporting the family-wide session policy
(SESSION_TTL_DAYS=30, SESSION_TTL_SECONDS=2_592_000,
SESSION_RENEW_THRESHOLD_SECONDS=3600, LOGOUT_PATHS) so every
bchen.dev app shares the same persistence window.
Introduces issueSessionCookie as the single mint site for
fastify-jwt sign + setCookie, replacing inlined jwt.sign +
setCookie calls in pages.ts and api/v1/auth.ts. The cookie now
carries Max-Age=SESSION_TTL_SECONDS so it persists across browser
restarts.
Converts requireAuth into a makeRequireAuth(config) factory; route
plugins build their own preHandler at registration time. Threads
through pages.ts, api/v1/auth.ts, and api/v1/files.ts.
SESSION_COOKIE_NAME stays 'token' in this commit so existing tests
remain green; the rename to 'nanodrop_session' lands in a follow-up.
JWT_EXPIRY env var is still read; its removal also lands in a
follow-up so each commit builds cleanly.
Brendan Chen
86870db726