fix: make mosaic init idempotent — detect existing config files

- mosaic-init bash script: detect existing SOUL.md/USER.md/TOOLS.md and
  prompt user to keep, import (re-use values as defaults), or overwrite.
  Non-interactive mode exits cleanly unless --force is passed.
  Overwrite creates timestamped backups before replacing files.

- launch.ts checkSoul(): prefer 'mosaic wizard' over legacy bash script
  when SOUL.md is missing, with fallback to mosaic-init.

- detect-install.ts: pre-populate wizard state with existing values when
  user chooses 'reconfigure', so they see current settings as defaults.

- soul-setup.ts: show existing agent name and communication style as
  defaults during reconfiguration.

- Added tests for reconfigure pre-population and reset non-population.

packages/cli/src/commands/launch.ts

@@ -54,12 +54,24 @@ function checkRuntime(cmd: string): void {
 function checkSoul(): void {
   const soulPath = join(MOSAIC_HOME, 'SOUL.md');
   if (!existsSync(soulPath)) {
-    console.log('[mosaic] SOUL.md not found. Running mosaic init...');
+    console.log('[mosaic] SOUL.md not found. Running setup wizard...');
+
+    // Prefer the TypeScript wizard (idempotent, detects existing files)
+    try {
+      const result = spawnSync(process.execPath, [process.argv[1]!, 'wizard'], {
+        stdio: 'inherit',
+      });
+      if (result.status === 0 && existsSync(soulPath)) return;
+    } catch {
+      // Fall through to legacy init
+    }
+
+    // Fallback: legacy bash mosaic-init
     const initBin = join(MOSAIC_HOME, 'tools', '_scripts', 'mosaic-init');
     if (existsSync(initBin)) {
       spawnSync(initBin, [], { stdio: 'inherit' });
     } else {
-      console.error('[mosaic] mosaic-init not found. Run: mosaic wizard');
+      console.error('[mosaic] Setup failed. Run: mosaic wizard');
       process.exit(1);
     }
   }