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/arkscope-vendor.test.ts

@@ -0,0 +1,43 @@
+import { existsSync, readdirSync, readFileSync, statSync } from 'fs'
+import { join } from 'path'
+import { describe, expect, it } from 'vitest'
+
+const VENDOR_ROOT = 'packages/client/src/vendor/arkscore'
+
+const listFiles = (dir: string): string[] =>
+  readdirSync(dir).flatMap((name) => {
+    const full = join(dir, name)
+    return statSync(full).isDirectory() ? listFiles(full) : [full]
+  })
+
+describe('ArkScope vendored components', () => {
+  const vendorFiles = listFiles(VENDOR_ROOT)
+
+  it('contains no art assets (images, audio, video)', () => {
+    const assetPattern = /\.(png|jpe?g|webp|mp3|mp4)$/i
+    expect(vendorFiles.filter((file) => assetPattern.test(file))).toEqual([])
+  })
+
+  it('contains no references to upstream asset directories', () => {
+    for (const file of vendorFiles) {
+      const content = readFileSync(file, 'utf8')
+      expect(content, `${file} must not reference upstream assets`).not.toMatch(
+        /src\/assets|public\/assets/,
+      )
+    }
+  })
+
+  it('keeps PROVENANCE.md with the pinned upstream commit hash', () => {
+    const provenancePath = join(VENDOR_ROOT, 'PROVENANCE.md')
+    expect(existsSync(provenancePath)).toBe(true)
+
+    const provenance = readFileSync(provenancePath, 'utf8')
+    expect(provenance).toContain('78f3763b0a48608eae00c27ac837449a32bd93df')
+    expect(provenance).toContain('https://github.com/triplepiers/ArkScope')
+  })
+
+  it('vendors no more than 3 components (guards against bulk re-import)', () => {
+    const componentCount = vendorFiles.filter((file) => file.endsWith('index.vue')).length
+    expect(componentCount).toBeLessThanOrEqual(3)
+  })
+})