fix(plugins): preserve frozen hosted workers on stale library

tests/unit/coding-capability-registry.test.ts

@@ -273,6 +273,7 @@ describe('CodingCapabilityRegistry', () => {
     const resolve = vi.fn(async () => frozenSnapshot);
     const effectiveResolver = {
       resolve,
+      resolveForInvocation: resolve,
       getSkillSources: vi.fn(async () => []),
       getPolicyState: vi.fn(() => hostedPolicy),
       getInstalledDefinition: vi.fn(async () => hostedDefinition),
@@ -400,8 +401,10 @@ describe('CodingCapabilityRegistry', () => {
     const resolve = vi.fn(async ({ role }: { role: 'parent' | 'child' }) => (
       role === 'child' ? { ...disabled, unavailableReasons: [] } : current
     ));
+    const resolveForInvocation = vi.fn(async () => current);
     const effectiveResolver = {
       resolve,
+      resolveForInvocation,
       getSkillSources: vi.fn(async () => [{
         id: 'web-search', pluginId: definition.id, packageRoot: 'C:/packages/web-search',
         directory: 'C:/packages/web-search/skills/web-search', entryPath: 'SKILL.md',
@@ -461,6 +464,7 @@ describe('CodingCapabilityRegistry', () => {
       capability_id: 'web-search.search', operation: 'search',
       payload_schema: 'web-search.v1', billing: { status: 'settled', actual_points: '1.00' },
     });
+    expect(resolveForInvocation).toHaveBeenCalledOnce();
 
     current = disabled;
     const stale = await capabilityRegistry.invoke({
@@ -497,6 +501,7 @@ describe('CodingCapabilityRegistry', () => {
     };
     const effectiveResolver = {
       resolve: vi.fn(async () => currentSnapshot),
+      resolveForInvocation: vi.fn(async () => currentSnapshot),
       getSkillSources: vi.fn(async () => []),
       getPolicyState: vi.fn(() => policy),
     } as unknown as EffectivePluginResolver;
@@ -509,7 +514,7 @@ describe('CodingCapabilityRegistry', () => {
     });
 
     expect(result.details).toMatchObject({ success: false, code: 'plugin_not_enabled' });
-    expect(effectiveResolver.resolve).toHaveBeenCalledWith(expect.objectContaining({
+    expect(effectiveResolver.resolveForInvocation).toHaveBeenCalledWith(expect.objectContaining({
       projectId: context.projectId,
       projectPath: context.projectPath,
       role: 'parent',