refactor: restructure bastion as pnpm monorepo (@lab/shared, @lab/bastion, @lab/cli)

- Split into 3 workspace packages: shared (types/constants), bastion (server), cli
- CLI binary renamed from "bastion" to "lab"
- Cross-package imports via @lab/shared and @lab/bastion workspace references
- Extracted BastionConfig, BastionState, HardwareInfo types into @lab/shared
- Added APP_NAME/APP_VERSION constants
- tsconfig.base.json with project references for build ordering
- Root workspace scripts: build, test, typecheck, clean

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

bastion/tsconfig.base.json

@@ -0,0 +1,25 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "lib": ["ES2022"],
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "declaration": true,
+    "declarationMap": true,
+    "sourceMap": true,
+    "composite": true,
+    "incremental": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noImplicitReturns": true,
+    "noFallthroughCasesInSwitch": true,
+    "exactOptionalPropertyTypes": true,
+    "noUncheckedIndexedAccess": true,
+    "isolatedModules": true,
+    "resolveJsonModule": true
+  }
+}