Cookbook scheduler: calendar events drive model serve windows (experimental, feature-flagged)

Add a calendar-driven scheduler so a user can pick a model in Cookbook, click "Schedule…" instead of "Launch", choose time windows + days of the week + (optional) end date, and have Odysseus auto-launch the serve when the window starts and hard-kill it when the window ends. The calendar IS the source of truth — events on a designated calendar are interpreted as serve schedules, so editing the event in the calendar UI immediately changes the schedule.

Whole feature is gated by setting `cookbook_scheduler_enabled` (default False). Disabling the setting silences the reconciler and the API refuses requests; setting + three new files = entire surface, easy to revert.

New files:
  - src/cookbook_scheduler.py — background reconciler: ticks every 60s, reads next ±90s of calendar events on the designated calendar, launches/kills serves to match. Honors "refuse if GPUs busy" (skips with reason, no retry). Adopts pre-existing manual serves matching the event's model so window-end cleanup still applies. Tags scheduler-owned tasks with `_scheduledBy: <event_uid>` so it never kills serves it doesn't own.
  - routes/cookbook_schedule_routes.py — POST /api/cookbook/schedule/from-cookbook builds RRULE+ICS events from the modal's input (model, slots[], days[], until). GET /upcoming returns the next 24h with per-event status (scheduled / running / adopted / skipped / failed / ended) for the UI. POST /reconcile-now manually kicks the reconciler.
  - static/js/cookbookSchedule.js — Schedule button click handler + modal. Daily/hourly time slot picker, multi-slot ("+ add another time slot"), weekday chips with Weekdays/Weekend/Every-day quicksets, optional Until date. Calls /from-cookbook on save. Whole module is a single IIFE; deleting the file plus its <script> tag removes the UI surface.

Existing files touched (minimal):
  - app.py: register the new router + add the reconcile loop as a startup task (~10 lines, all in one block). Reconcile loop checks the feature flag on every tick, so leaving it running with the flag off costs ~one settings lookup per minute.
  - static/index.html: one new <script> tag for cookbookSchedule.js.
  - static/js/cookbookServe.js: add a "Schedule…" button next to the existing Launch button. Hidden by default; cookbookSchedule.js reveals it after confirming the feature flag is on.
  - static/style.css: ~80 lines for the modal styles (mobile-aware via @media).

User choices baked in:
  - Calendar events are the source of truth.
  - Refuse to launch if GPUs busy (skip + log reason in scheduler.events[uid].reason).
  - Hard kill at event end.
  - No retry on a skipped event within the window.
  - Multi-slot per day supported (one calendar event per slot, shared RRULE).
  - Pre-existing manual serves get adopted at window start so they're killed at end.

Known follow-ups (not in this commit):
  - Settings UI to pick the schedule calendar + toggle the feature flag.
  - Calendar event color/badge for status (running/skipped/failed).
  - "Lazy launch on first request" — currently launches at event start. Replacing _launch_serve with a proxy that defers vllm until the first chat request is a contained future change.

static/style.css

@@ -35736,3 +35736,96 @@ body.theme-frosted .modal {
      is already ≥16px and never zoomed — leave it so we don't shrink it. */
   .doc-email-richbody.doc-font-m { font-size: 16px !important; }
 }
+
+/* ── Cookbook Schedule modal (feature-flagged) ─────────────────────── */
+.cookbook-schedule-modal-backdrop {
+  position: fixed; inset: 0; background: rgba(0,0,0,.5);
+  display: flex; align-items: center; justify-content: center;
+  z-index: 10000;
+}
+.cookbook-schedule-modal {
+  background: var(--bg-secondary, #1e1e22);
+  color: var(--text-primary, #e6e6e6);
+  border: 1px solid var(--border, #2d2d33);
+  border-radius: 12px; width: min(560px, 92vw); max-height: 90vh;
+  display: flex; flex-direction: column; overflow: hidden;
+  box-shadow: 0 12px 40px rgba(0,0,0,.5);
+}
+.cookbook-schedule-modal-header {
+  padding: 14px 18px; border-bottom: 1px solid var(--border, #2d2d33);
+  display: flex; align-items: center; justify-content: space-between;
+}
+.cookbook-schedule-close {
+  background: transparent; border: none; color: inherit;
+  font-size: 22px; line-height: 1; cursor: pointer; padding: 0 6px;
+}
+.cookbook-schedule-modal-body { padding: 16px 18px; overflow-y: auto; }
+.cookbook-schedule-section { margin-bottom: 16px; }
+.cookbook-schedule-section-label {
+  display: block; font-size: 12px; opacity: .7;
+  margin-bottom: 6px; text-transform: uppercase; letter-spacing: .04em;
+}
+.cookbook-schedule-slot {
+  display: flex; align-items: center; gap: 6px; margin-bottom: 6px;
+}
+.cookbook-schedule-slot input[type="time"] {
+  background: var(--bg-primary, #131316); color: inherit;
+  border: 1px solid var(--border, #2d2d33); border-radius: 6px;
+  padding: 6px 8px; font: inherit;
+}
+.cookbook-schedule-slot-remove {
+  background: transparent; border: 1px solid var(--border, #2d2d33);
+  color: inherit; border-radius: 6px; width: 28px; height: 28px;
+  cursor: pointer; font-size: 18px; line-height: 1;
+}
+.cookbook-schedule-add-slot {
+  background: transparent; color: var(--accent, #6aa8ff);
+  border: 1px dashed var(--border, #2d2d33); border-radius: 6px;
+  padding: 6px 10px; cursor: pointer; font: inherit; margin-top: 4px;
+}
+.cookbook-schedule-days {
+  display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 6px;
+}
+.cookbook-schedule-day {
+  display: inline-flex; align-items: center; gap: 4px;
+  padding: 6px 10px; border: 1px solid var(--border, #2d2d33);
+  border-radius: 999px; cursor: pointer; font-size: 13px;
+  user-select: none;
+}
+.cookbook-schedule-day input { display: none; }
+.cookbook-schedule-day.active {
+  background: var(--accent, #6aa8ff); color: #fff;
+  border-color: var(--accent, #6aa8ff);
+}
+.cookbook-schedule-day-quickset {
+  display: flex; gap: 6px; flex-wrap: wrap;
+}
+.cookbook-schedule-day-quickset button {
+  background: transparent; color: var(--text-secondary, #aaa);
+  border: 1px solid var(--border, #2d2d33); border-radius: 6px;
+  padding: 4px 8px; cursor: pointer; font-size: 12px;
+}
+.cookbook-schedule-until { display: flex; gap: 16px; flex-wrap: wrap; }
+.cookbook-schedule-until label {
+  display: inline-flex; align-items: center; gap: 6px;
+}
+.cookbook-schedule-until-date {
+  background: var(--bg-primary, #131316); color: inherit;
+  border: 1px solid var(--border, #2d2d33); border-radius: 6px;
+  padding: 4px 8px;
+}
+.cookbook-schedule-error {
+  color: #ff6b6b; background: rgba(255,107,107,.08);
+  border: 1px solid rgba(255,107,107,.3); border-radius: 6px;
+  padding: 8px 12px; font-size: 13px;
+}
+.cookbook-schedule-modal-footer {
+  padding: 12px 18px; border-top: 1px solid var(--border, #2d2d33);
+  display: flex; justify-content: flex-end; gap: 8px;
+}
+
+/* Mobile (Firefox + others): single-column slot rows + larger touch targets. */
+@media (max-width: 600px) {
+  .cookbook-schedule-modal { width: 96vw; }
+  .cookbook-schedule-day { padding: 8px 14px; font-size: 14px; }
+}