v0.2.0 — Named schedules, the weekly-hours editor, and a CLI

Named availability schedules, a redesigned weekly-hours editor, a CLI
installer, and a body of race-condition and booking-page fixes — most found
by the dual-model review process this repo runs on every change.

Added

• Named availability schedules (migration 0007): a host can keep
  several schedules ("Working hours", "Evenings") and assign one per event
  type; unassigned event types follow the default. Guarded at the database,
  not in application code: one default per user via a partial unique index,
  delete blocked while an event type still points at a schedule, and the
  event-type ↔ schedule link written with a scalar-subquery guard so a
  concurrent schedule delete cannot leave a dangling reference.
• Redesigned weekly-hours editor: per-day toggle switches and native
  time inputs with one or more ranges per day (lunch-break splits), a
  no-JavaScript "+ Add range" round trip, and a CSS-only show/hide — the
  whole editor works with scripts disabled. In-progress typing survives
  validation errors and add-range round trips instead of reverting.
• punctual-sh CLI (cli/, published to npm; installs a punctual
  binary): punctual init runs the whole self-host quick start — creates
  the D1/KV/R2/Queues resources, writes their ids into wrangler.toml,
  generates secrets, migrates and deploys, idempotently and resumably —
  and refuses to adopt or overwrite any resource it did not create, in any
  Cloudflare account, by design. punctual slots prints live availability
  from a running instance. Terminal identity per the brand: the wordmark's
  green colon, shape-distinct status glyphs, no color when piped or under
  NO_COLOR.
• Booking page defaults to today's slots on first load instead of "Pick a
  day", and the calendar highlights the selected day (and moves the
  highlight when the guest switches days).
• New accounts are bookable from creation: a default schedule is
  provisioned at signup and backfilled on login for accounts that predate
  it — previously a new host had no availability until they saved the form
  once.
• Optional GA4 analytics, scoped strictly to the marketing/docs pages.

Fixed

• Cross-table slug race (migration 0008): user signup and team
  creation share one slug namespace but arbitrated it in application code;
  two concurrent requests could claim the same slug. A slug_claims table
  now makes the database the arbiter, written in the same atomic batch as
  the row that claims the name.
• A family of agenda-question edge cases: duplicated question when a
  host's custom wording matches the builtin, legacy answers hidden after a
  same-labeled replacement, stale-form loss of answers when a host edits
  mid-fill, and a blank direct answer shadowing a filled older one.
• Calendar month clamping no longer hides the last bookable day from
  guests far behind the host's timezone, and the day panel can no longer
  render for a month the calendar isn't showing.
• Email templates: rendered and verified in real clients; fixed a broken
  avatar-alt fallback, a raw IANA timezone id in the footer, and spacing
  between the secondary action and the footer rule.
• The public-page footer wordmark links to punctual.sh (new tab) rather
  than the deployment's own homepage, and no longer inherits a
  deployment's custom brand name.
• Flaky wall-clock tests (rate limiter, "defaults to today") made
  deterministic by measuring elapsed time instead of assuming it.