feat: add TypeScript installation wizard with @clack/prompts TUI

Replace bash mosaic-init with a modern 9-stage wizard:
- SOUL.md identity, USER.md profile, TOOLS.md configuration
- Runtime detection (Claude, Codex, OpenCode) + MCP setup
- Skills catalog with categorized selection
- Quick Start and Advanced modes
- HeadlessPrompter for --non-interactive and CI usage
- ConfigService abstraction layer for future DB migration
- Bundled as single dist/mosaic-wizard.mjs via tsdown
- mosaic init now prefers wizard when Node.js is available
- 30 tests covering stages, templates, and integration

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

src/stages/soul-setup.ts

@@ -0,0 +1,73 @@
+import type { WizardPrompter } from '../prompter/interface.js';
+import type { WizardState, CommunicationStyle } from '../types.js';
+import { DEFAULTS } from '../constants.js';
+
+export async function soulSetupStage(
+  p: WizardPrompter,
+  state: WizardState,
+): Promise<void> {
+  if (state.installAction === 'keep') return;
+
+  p.separator();
+  p.note(
+    'Your agent identity defines how AI assistants behave,\n' +
+      'their principles, and communication style.\n' +
+      'This creates SOUL.md.',
+    'Agent Identity',
+  );
+
+  if (!state.soul.agentName) {
+    state.soul.agentName = await p.text({
+      message: 'What name should agents use?',
+      placeholder: 'e.g., Jarvis, Assistant, Mosaic',
+      defaultValue: DEFAULTS.agentName,
+      validate: (v) => {
+        if (v.length === 0) return 'Name cannot be empty';
+        if (v.length > 50) return 'Name must be under 50 characters';
+      },
+    });
+  }
+
+  if (state.mode === 'advanced') {
+    if (!state.soul.roleDescription) {
+      state.soul.roleDescription = await p.text({
+        message: 'Agent role description',
+        placeholder: 'e.g., execution partner and visibility engine',
+        defaultValue: DEFAULTS.roleDescription,
+      });
+    }
+  } else {
+    state.soul.roleDescription ??= DEFAULTS.roleDescription;
+  }
+
+  if (!state.soul.communicationStyle) {
+    state.soul.communicationStyle = await p.select<CommunicationStyle>({
+      message: 'Communication style',
+      options: [
+        { value: 'direct', label: 'Direct', hint: 'Concise, no fluff, actionable' },
+        { value: 'friendly', label: 'Friendly', hint: 'Warm but efficient, conversational' },
+        { value: 'formal', label: 'Formal', hint: 'Professional, structured, thorough' },
+      ],
+      initialValue: 'direct',
+    });
+  }
+
+  if (state.mode === 'advanced') {
+    if (!state.soul.accessibility) {
+      state.soul.accessibility = await p.text({
+        message: 'Accessibility preferences',
+        placeholder:
+          "e.g., ADHD-friendly chunking, dyslexia-aware formatting, or 'none'",
+        defaultValue: 'none',
+      });
+    }
+
+    if (!state.soul.customGuardrails) {
+      state.soul.customGuardrails = await p.text({
+        message: 'Custom guardrails (optional)',
+        placeholder: 'e.g., Never auto-commit to main',
+        defaultValue: '',
+      });
+    }
+  }
+}