feat: refactor project structure + add pcguard + AGENT_VERIFY injection

- Restructure: pcexec/ and safe-restart/ → plugin/{tools,core,commands}
- New pcguard Go binary: validates AGENT_VERIFY, AGENT_ID, AGENT_WORKSPACE
- pcexec now injects AGENT_VERIFY env + appends openclaw bin to PATH
- plugin/index.ts: unified TypeScript entry point with resolveOpenclawPath()
- install.mjs: support --openclaw-profile-path, install pcguard, new paths
- README: updated structure docs + security limitations note
- Removed old root index.js and openclaw.plugin.json

plugin/tsconfig.json

@@ -0,0 +1,19 @@
+{
+  "compilerOptions": {
+    "target": "ES2020",
+    "module": "commonjs",
+    "lib": ["ES2020"],
+    "outDir": "../dist/padded-cell",
+    "rootDir": ".",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "declaration": true,
+    "declarationMap": true,
+    "sourceMap": true,
+    "resolveJsonModule": true
+  },
+  "include": ["./**/*.ts"],
+  "exclude": ["node_modules", "../dist", "**/*.test.ts"]
+}