protocol: drop Fable 5 from the model table — Anthropic withdrew it [skip-proto-bump]

Fable 5 (claude-fable-5 + the [1m] variant) was pulled by Anthropic, so a
session created with it now errors at the SDK. Delete both entries rather
than mark them deprecated: a withdrawn model isn't a superseded one we
keep around for historical-session labels — it's gone, and leaving it in
the picker only lets users select a dead model.

Wire-neutral: the protocol `model` field is `z.string()` (free passthrough,
not a closed enum), so removing table entries changes no wire schema —
only the iOS picker contents + `/model` validation + prettyModel labels,
all app-bundled. Hence [skip-proto-bump]; daemon/menubar need no re-release
(they treat model as an opaque string and don't surface the picker).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: yyq1025

packages/protocol/src/models.ts

@@ -92,16 +92,6 @@ export interface ModelMetadata {
  */
 export const MODEL_METADATA: Record<string, ModelMetadata> = {
   // ─── Current models ─────────────────────────────────────────────────
-  // Fable is a separate tier alongside Opus (NOT a generational
-  // replacement — Opus 4.8 stays current + default).
-  "claude-fable-5[1m]": {
-    displayName: "Fable 5 1M",
-    contextWindow: 1_000_000,
-  },
-  "claude-fable-5": {
-    displayName: "Fable 5",
-    contextWindow: 200_000,
-  },
   "claude-opus-4-8[1m]": {
     displayName: "Opus 4.8 1M",
     isDefault: true,