refactor: simplify paired review system and add reviewer container isolation

Phase 1 — Strip over-engineering (-3,665 lines):
- DB tables: 7 → 3 (remove executions, approvals, artifacts, events)
- Task statuses: 11 → 5 (active, review_ready, in_review, merge_ready, completed)
- Remove plan governance, event sourcing, gate/verdict, freshness guards
- paired-execution-context: 980 → 299 lines
- Session commands: remove /risk, /plan, /approve-plan, /request-plan-changes

Phase 2 — Container isolation for reviewers:
- Add container-runtime.ts (Docker abstraction)
- Add credential-proxy.ts (API key injection without container exposure)
- Add container-runner.ts (reviewer-specific read-only mount + tmpfs)
- Add container/Dockerfile + agent-runner (Chromium, Claude Code, Codex)
- agent-runner.ts: auto-route reviewer execution to container mode

container/agent-runner/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "ejclaw-reviewer-runner",
+  "version": "1.0.0",
+  "type": "module",
+  "description": "Reviewer agent runner for EJClaw containers",
+  "main": "dist/index.js",
+  "scripts": {
+    "build": "tsc",
+    "dev": "tsc --watch"
+  },
+  "dependencies": {
+    "@anthropic-ai/claude-code": "^1.0.0"
+  },
+  "devDependencies": {
+    "typescript": "^5.7.0"
+  }
+}

container/agent-runner/src/index.ts

@@ -0,0 +1,139 @@
+/**
+ * EJClaw Reviewer Container Agent Runner
+ *
+ * Runs inside a Docker container. Reads input from stdin,
+ * invokes Claude Code or Codex, writes output to stdout
+ * via marker-delimited JSON.
+ *
+ * The project directory is mounted read-only — the reviewer
+ * can read/test code but cannot modify it.
+ */
+import { claude } from '@anthropic-ai/claude-code';
+import fs from 'fs';
+import path from 'path';
+
+// ── Protocol markers (must match host's agent-protocol.ts) ────────
+const OUTPUT_START_MARKER = '---EJCLAW_OUTPUT_START---';
+const OUTPUT_END_MARKER = '---EJCLAW_OUTPUT_END---';
+
+// ── Types ─────────────────────────────────────────────────────────
+interface ContainerInput {
+  prompt: string;
+  sessionId?: string;
+  groupFolder: string;
+  chatJid: string;
+  runId: string;
+  isMain: boolean;
+  assistantName?: string;
+}
+
+interface ContainerOutput {
+  status: 'success' | 'error';
+  result: string | null;
+  newSessionId?: string;
+  error?: string;
+  phase: 'final';
+}
+
+// ── Helpers ───────────────────────────────────────────────────────
+
+function emitOutput(output: ContainerOutput): void {
+  const json = JSON.stringify(output);
+  process.stdout.write(`${OUTPUT_START_MARKER}${json}${OUTPUT_END_MARKER}\n`);
+}
+
+function readStdinJson(): Promise<ContainerInput> {
+  return new Promise((resolve, reject) => {
+    const chunks: Buffer[] = [];
+    process.stdin.on('data', (chunk) => chunks.push(chunk));
+    process.stdin.on('end', () => {
+      try {
+        resolve(JSON.parse(Buffer.concat(chunks).toString()));
+      } catch (err) {
+        reject(new Error(`Failed to parse stdin JSON: ${err}`));
+      }
+    });
+    process.stdin.on('error', reject);
+  });
+}
+
+// ── Main ──────────────────────────────────────────────────────────
+
+async function main(): Promise<void> {
+  const input = await readStdinJson();
+
+  // Load group CLAUDE.md if present
+  const groupClaudeMd = path.join('/workspace/group', 'CLAUDE.md');
+  const systemPromptParts: string[] = [];
+  if (fs.existsSync(groupClaudeMd)) {
+    systemPromptParts.push(fs.readFileSync(groupClaudeMd, 'utf-8'));
+  }
+
+  // Reviewer-specific instructions
+  systemPromptParts.push(
+    'You are a code reviewer. The project directory is mounted read-only.',
+    'You can read files, run tests, and analyze code, but you cannot modify any source files.',
+    'Focus on: correctness, security, performance, and test coverage.',
+  );
+
+  const systemPrompt = systemPromptParts.join('\n\n');
+
+  try {
+    const result = await claude({
+      prompt: input.prompt,
+      systemPrompt,
+      options: {
+        allowedTools: [
+          'Read',
+          'Bash',
+          'Glob',
+          'Grep',
+          'LS',
+          'Agent',
+          'WebSearch',
+          'WebFetch',
+        ],
+        maxTurns: 30,
+        cwd: '/workspace/project',
+      },
+    });
+
+    // Extract text from result
+    const text =
+      typeof result === 'string'
+        ? result
+        : Array.isArray(result)
+          ? result
+              .filter(
+                (b: { type: string; text?: string }) => b.type === 'text',
+              )
+              .map((b: { text?: string }) => b.text || '')
+              .join('\n')
+          : String(result);
+
+    emitOutput({
+      status: 'success',
+      result: text,
+      phase: 'final',
+    });
+  } catch (err) {
+    const errorMsg = err instanceof Error ? err.message : String(err);
+    emitOutput({
+      status: 'error',
+      result: null,
+      error: errorMsg,
+      phase: 'final',
+    });
+  }
+}
+
+main().catch((err) => {
+  console.error('Fatal container error:', err);
+  emitOutput({
+    status: 'error',
+    result: null,
+    error: `Fatal: ${err instanceof Error ? err.message : String(err)}`,
+    phase: 'final',
+  });
+  process.exit(1);
+});

container/agent-runner/tsconfig.json

@@ -0,0 +1,14 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "Node16",
+    "moduleResolution": "Node16",
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "declaration": true
+  },
+  "include": ["src/**/*"]
+}