chore: rename Claudeman to Codeman

Full product rename across 109 files (~834 occurrences):
- Env vars: CLAUDEMAN_* → CODEMAN_*
- Data dirs: ~/.claudeman/ → ~/.codeman/, ~/claudeman-cases/ → ~/codeman-cases/
- tmux prefix: claudeman- → codeman-
- localStorage: claudeman-* → codeman-*
- Package/CLI: claudeman → codeman
- GitHub repo: Ark0N/Claudeman → Ark0N/Codeman
- systemd service: claudeman-web → codeman-web
- Class: ClaudemanApp → CodemanApp

Migration infrastructure for seamless transition:
- state-store.ts: auto-migrates data directories on startup
- tmux-manager.ts: dual-prefix detection (legacy claudeman- sessions)
- app.js: localStorage key migration (preserves old keys)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

mobile-test/settings.test.ts

@@ -43,7 +43,7 @@ describe('Settings Modal', () => {
       await context.close();
     });
 
-    it('uses claudeman-app-settings-mobile localStorage key', async () => {
+    it('uses codeman-app-settings-mobile localStorage key', async () => {
       const key = await page.evaluate(() => {
         return (window as any).app?.getSettingsStorageKey?.() ?? null;
       });
@@ -53,10 +53,10 @@ describe('Settings Modal', () => {
       } else {
         // Verify by checking what key is used when saving settings
         await page.evaluate(() => {
-          localStorage.setItem('claudeman-app-settings-mobile', JSON.stringify({ testFlag: true }));
+          localStorage.setItem('codeman-app-settings-mobile', JSON.stringify({ testFlag: true }));
         });
         const stored = await page.evaluate(() => {
-          return localStorage.getItem('claudeman-app-settings-mobile');
+          return localStorage.getItem('codeman-app-settings-mobile');
         });
         expect(stored).toContain('testFlag');
       }