fix(queue): persist "Print Anyway" so scheduler stops re-flagging it

When the user clicked Print Anyway on a filament-deficit warning, the
  acknowledgement was one-shot. The route cleared manual_start and
  filament_short, then the next scheduler tick re-ran
  compute_deficit_for_queue_item against identical spool state, found
  the same deficit, and re-set both flags. The item bounced between
  "user said anyway" and "scheduler re-blocked" — every Play click
  returned 409, every confirm got rolled back on the next tick.

  Add a persistent acknowledgement flag on the queue item:

  - New column `skip_filament_check` on print_queue. SQLite + Postgres
    migration branched on is_sqlite() so Postgres doesn't reject
    DEFAULT 0 on BOOLEAN.

  - PrintQueueItemCreate + PrintQueueItemResponse schemas + the
    TypeScript types carry the field.

  - POST /print-queue/{id}/start with skip_filament_check=true now
    ALSO sets item.skip_filament_check = True (not just clearing
    manual_start / filament_short).

  - PrintScheduler._block_on_filament_deficit short-circuits to
    False — no compute, no flag-setting, no notification — when
    item.skip_filament_check is True. We trust the operator's
    decision and stop fighting them.

  - PrintModal at queue-creation time threads
    skip_filament_check=true into the create payload when the user
    clicks Print Anyway on the frontend deficit warning, so a print
    that was warned-then-acknowledged at add-to-queue time goes in
    pre-acknowledged — scheduler never blocks it on first tick.

  Flag is not auto-cleared on spool swap by design: if remaining is
  now sufficient, the check returns no deficit anyway, so the flag
  is moot. Auto-clearing would add lifecycle complexity without
  changing behaviour.

  AMS Backup awareness (the other half of the discussion) intentionally
  NOT included — verified the H2D's bit-26 of print.cfg toggles with
  the printer-side AMS Backup setting, but the X1C's cfg has a
  different shape entirely and verifying every model family isn't
  realistic. Silently under-warning would be worse than always
  per-slot. The check stays single-slot for now.

frontend/src/api/client.ts

@@ -1898,6 +1898,11 @@ export interface PrintQueueItem {
   // any required slot's grams (#1496). Surfaced on the queue row as a
   // "filament short" badge; cleared on a successful ▶ click (live recheck).
   filament_short: boolean;
+  // Persistent "Print Anyway" acknowledgement — once true the scheduler
+  // skips the deficit check for this item (#1698-followup). Set by the
+  // start route when skip_filament_check=true, or at queue creation if
+  // PrintModal's deficit warning was acknowledged.
+  skip_filament_check: boolean;
   ams_mapping: number[] | null;  // AMS slot mapping for multi-color prints
   filament_overrides: Array<{ slot_id: number; type: string; color: string; color_name?: string; force_color_match?: boolean }> | null;  // Filament overrides for model-based assignment
   plate_id: number | null;  // Plate ID for multi-plate 3MF files
@@ -1966,6 +1971,9 @@ export interface PrintQueueItemCreate {
   require_previous_success?: boolean;
   auto_off_after?: boolean;
   manual_start?: boolean;  // Requires manual trigger to start (staged)
+  // PrintModal "Print Anyway" on the deficit warning — persisted so the
+  // scheduler doesn't immediately re-flag this item (#1698-followup).
+  skip_filament_check?: boolean;
   ams_mapping?: number[] | null;  // AMS slot mapping for multi-color prints
   plate_id?: number | null;  // Plate ID for multi-plate 3MF files
   // Print options