Phase 005: vendor ArkScope, land the Arco style baseline, and fix bridge interpreter resolution

- Vendor ArkScope decorative layers (ScrambleTitle / IsometricWave) with provenance notes; decorative-only per AGENTS.md red lines
- Migrate theme tokens to Arco, register the Arco theme, and add hook adapter composables (useMessage / useDialog / useNotification) with matching signatures
- Sample pages: LoginView and AppSidebar on the new baseline; docs/arco-mapping.md and docs/ui-baseline.md land
- agent-bridge: prefer the PM-selected venv from facts.json over legacy in-tree venvs (legacy lacks the mcp extra, so every MCP server showed 0 tools / not connected)
- agent-bridge python (vendored, deliberate deviation): MCP discovery import fallback and pyyaml -> hermes_yaml so plugins and MCP work under the PM env; install the mcp extra via `hermes pm install --extra mcp`
- Chat-chain fragment: docs/chat-chain-changes/2026-10-17-phase005-arkscope-baseline.md

Verified: harness:check, test (2020 passed), test:e2e (30 passed), build all green; manual: plugins 100/0 warnings, MCP 6/6 servers connected with 104 tools.

tests/client/provider-card-built-in-action.test.ts

@@ -145,6 +145,11 @@ vi.mock('naive-ui', () => ({
   useDialog: () => dialogMock,
 }))
 
+// ProviderCard reads message/dialog through the Arco adapter layer, not
+// naive-ui's composables, so the mock must target the adapter modules.
+vi.mock('@/composables/useMessage', () => ({ useMessage: () => messageMock }))
+vi.mock('@/composables/useDialog', () => ({ useDialog: () => dialogMock }))
+
 vi.mock('@/stores/hermes/models', () => ({ useModelsStore: () => modelsStoreMock }))
 vi.mock('@/stores/hermes/app', () => ({ useAppStore: () => appStoreMock }))
 vi.mock('@/stores/hermes/chat', () => ({ useChatStore: () => chatStoreMock }))