feat: paired review system overhaul — unified service, configurable agents, silent output removal

- Remove UNIFIED_MODE legacy: single service manages all 3 Discord bots
- Add OWNER_AGENT_TYPE / REVIEWER_AGENT_TYPE env vars for configurable agent selection
- Fix Discord channel routing: reviewer output goes through correct bot (discord/discord-review)
- Fix channel name assignment: explicit names prevent agentTypeFilter collision
- Remove silent output suppression system: harness-level protections replace prompt workarounds
- Add reviewer approval detection: DONE marker on first line stops ping-pong
- Include user's original message in reviewer prompt for context
- Fix round_trip_count auto-reset on new user message
- Fix session ID conflict: reviewer doesn't reuse owner's session
- Fix pending progress text flush in runner on close sentinel
- Promote buffered intermediate text to final result when result event has no text
- Remove legacy files: .env.codex.example, .env.codex-review.example, migrate-unify.cjs
- Update CLAUDE.md: server-side build deployment, unified architecture docs

src/agent-runner.ts

@@ -13,6 +13,7 @@ import {
   IDLE_TIMEOUT,
 } from './config.js';
 import { prepareGroupEnvironment } from './agent-runner-environment.js';
+import { getEnv } from './env.js';
 export {
   type AvailableGroup,
   writeGroupsSnapshot,
@@ -74,7 +75,7 @@ export async function runAgentProcess(
   // as a host process. This provides kernel-level write protection.
   const isReviewerContainer =
     envOverrides?.EJCLAW_REVIEWER_RUNTIME === '1' &&
-    process.env.REVIEWER_CONTAINER_ENABLED !== '0';
+    getEnv('REVIEWER_CONTAINER_ENABLED') !== '0';
   if (isReviewerContainer) {
     const ownerWorkspaceDir =
       envOverrides?.EJCLAW_WORK_DIR || group.workDir || process.cwd();