feat(mosaic): migrate install wizard from v0 to v1

Complete port of the ~2000 LOC mosaic install wizard from v0. Migrates
all 27 source files across the prompter, config, platform, template,
runtime, skills, and stages subsystems to v1 ESM/NodeNext conventions.

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

pnpm-lock.yaml

@@ -386,7 +386,26 @@ importers:
         version: 2.1.9(@types/node@22.19.15)(lightningcss@1.31.1)
 
   packages/mosaic:
+    dependencies:
+      '@clack/prompts':
+        specifier: ^0.9.1
+        version: 0.9.1
+      commander:
+        specifier: ^12.1.0
+        version: 12.1.0
+      picocolors:
+        specifier: ^1.1.1
+        version: 1.1.1
+      yaml:
+        specifier: ^2.6.1
+        version: 2.8.2
+      zod:
+        specifier: ^3.23.8
+        version: 3.25.76
     devDependencies:
+      '@types/node':
+        specifier: ^22.0.0
+        version: 22.19.15
       typescript:
         specifier: ^5.8.0
         version: 5.9.3