feat: enable/disable providers from settings

Adds a per-provider toggle in Settings → Providers, persisted via daemon
config, so users can turn off providers they don't have installed (or
don't want to use) without removing them from the registry.

Disabled providers stay visible everywhere — settings, `paseo provider
ls`, MCP `list_providers`, model/mode lists — marked as disabled rather
than silently filtered. Availability probes are skipped for them, and
attempts to launch an agent or fetch models/modes from a disabled
provider return a clear "Provider '<id>' is disabled" error.

Schema additions (`enabled` on `ProviderSnapshotEntry`, MCP provider
summary) are backward-compatible: optional with a default of true so
older clients continue to parse new daemon messages.

CLI: `paseo provider ls` gains an ENABLED column; JSON output includes
the new field.

packages/server/src/shared/messages.providers-snapshot.test.ts

@@ -0,0 +1,84 @@
+import { describe, expect, test } from "vitest";
+import {
+  GetProvidersSnapshotResponseMessageSchema,
+  ProviderSnapshotEntrySchema,
+  ProvidersSnapshotUpdateMessageSchema,
+} from "./messages.js";
+
+describe("provider snapshot message schemas", () => {
+  test("defaults missing provider snapshot entry enabled state to true", () => {
+    const parsed = ProviderSnapshotEntrySchema.parse({
+      provider: "codex",
+      status: "ready",
+      label: "Codex",
+    });
+
+    expect(parsed.enabled).toBe(true);
+  });
+
+  test("preserves disabled provider snapshot entries", () => {
+    const parsed = ProviderSnapshotEntrySchema.parse({
+      provider: "claude",
+      status: "unavailable",
+      enabled: false,
+      label: "Claude",
+    });
+
+    expect(parsed.enabled).toBe(false);
+  });
+
+  test("preserves enabled provider snapshot entries", () => {
+    const parsed = ProviderSnapshotEntrySchema.parse({
+      provider: "opencode",
+      status: "loading",
+      enabled: true,
+      label: "OpenCode",
+    });
+
+    expect(parsed.enabled).toBe(true);
+  });
+
+  test("defaults missing enabled state in providers snapshot response entries", () => {
+    const parsed = GetProvidersSnapshotResponseMessageSchema.parse({
+      type: "get_providers_snapshot_response",
+      payload: {
+        entries: [
+          {
+            provider: "codex",
+            status: "ready",
+            label: "Codex",
+          },
+          {
+            provider: "claude",
+            status: "unavailable",
+            enabled: false,
+            label: "Claude",
+          },
+        ],
+        generatedAt: "2026-04-24T00:00:00.000Z",
+        requestId: "req-providers",
+      },
+    });
+
+    expect(parsed.payload.entries.map((entry) => entry.enabled)).toEqual([true, false]);
+  });
+
+  test("defaults missing enabled state in providers snapshot update entries", () => {
+    const parsed = ProvidersSnapshotUpdateMessageSchema.parse({
+      type: "providers_snapshot_update",
+      payload: {
+        cwd: "/tmp/repo",
+        entries: [
+          {
+            provider: "codex",
+            status: "ready",
+            label: "Codex",
+          },
+        ],
+        generatedAt: "2026-04-24T00:00:00.000Z",
+      },
+    });
+
+    expect(parsed.payload.entries[0]?.enabled).toBe(true);
+  });
+});

packages/server/src/shared/messages.ts

@@ -98,7 +98,6 @@ import type {
   AgentPermissionRequest,
   AgentPermissionResponse,
   AgentPersistenceHandle,
-  ProviderSnapshotEntry,
   ProviderStatus,
   AgentRuntimeInfo,
   AgentTimelineItem,
@@ -169,9 +168,10 @@ const AgentModelDefinitionSchema: z.ZodType<AgentModelDefinition> = z.object({
   defaultThinkingOptionId: z.string().optional(),
 });
 
-const ProviderSnapshotEntrySchema: z.ZodType<ProviderSnapshotEntry> = z.object({
+export const ProviderSnapshotEntrySchema = z.object({
   provider: AgentProviderSchema,
   status: ProviderStatusSchema,
+  enabled: z.boolean().optional().default(true),
   error: z.string().optional(),
   models: z.array(AgentModelDefinitionSchema).optional(),
   modes: z.array(AgentModeSchema).optional(),