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>

test/file-link-click.test.ts

@@ -1,5 +1,5 @@
 /**
- * File Link Click Tests for Claudeman Web UI
+ * File Link Click Tests for Codeman Web UI
  *
  * Tests that file paths displayed in terminal output are clickable
  * and open the log viewer window correctly.
@@ -88,7 +88,7 @@ describe('File Link Click Tests', () => {
     closeBrowser();
 
     // Create test directory and log file
-    testDir = join(tmpdir(), `claudeman-link-test-${Date.now()}`);
+    testDir = join(tmpdir(), `codeman-link-test-${Date.now()}`);
     mkdirSync(testDir, { recursive: true });
     testLogFile = join(testDir, 'test.log');
     writeFileSync(testLogFile, '=== Test Log Started ===\n');
@@ -102,7 +102,7 @@ describe('File Link Click Tests', () => {
       browser(`open ${baseUrl}`);
       await new Promise(r => setTimeout(r, 2000));
       const title = browserJson<{ title: string }>('get title');
-      browserAvailable = title.title === 'Claudeman';
+      browserAvailable = title.title === 'Codeman';
     } catch (e) {
       console.warn('Browser not available, skipping browser tests:', (e as Error).message);
       browserAvailable = false;