fix(clean): correct project-tech field references and add sync vs clean disambiguation

- Fix Step 4.3: project.features → project.development_index,
  project.statistics → project._metadata
- Add project-guidelines.json learnings cleanup on session deletion
- Add sync vs clean disambiguation table explaining write vs reclaim

ccw/frontend/src/locales/zh/index.ts

@@ -41,6 +41,7 @@ import cliViewer from './cli-viewer.json';
 import team from './team.json';
 import terminalDashboard from './terminal-dashboard.json';
 import skillHub from './skill-hub.json';
+import nativeSession from './native-session.json';
 
 /**
  * Flattens nested JSON object to dot-separated keys
@@ -105,4 +106,5 @@ export default {
   ...flattenMessages(team, 'team'),
   ...flattenMessages(terminalDashboard, 'terminalDashboard'),
   ...flattenMessages(skillHub, 'skillHub'),
+  ...flattenMessages(nativeSession, 'nativeSession'),
 } as Record<string, string>;