content: add array properties to mock data for tag-pill testing

Added non-wikilink array properties (tags, tools, domains) to mock
frontmatter content so the upcoming tag-pill UI has realistic test data.

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

src/components/Inspector.test.tsx

@@ -27,6 +27,7 @@ is_a: Project
 Status: Active
 Owner: Luca Rossi
 Cadence: Weekly
+tags: [React, TypeScript, Tauri]
 Belongs to:
   - "[[responsibility/grow-newsletter]]"
 Related to:

src/mock-tauri.ts

@@ -27,6 +27,8 @@ title: Build Laputa App
 is_a: Project
 status: Active
 owner: Luca Rossi
+tags: [Tauri, React, TypeScript, CodeMirror]
+tools: [Vite, Vitest, Playwright]
 belongs_to:
   - "[[quarter/q1-2026]]"
 related_to:
@@ -251,6 +253,8 @@ title: Stock Screener — EMA200 Wick Bounce
 is_a: Experiment
 status: Active
 owner: Luca Rossi
+domains: [Finance, Quantitative Analysis]
+tools: [Python, pandas, TradingView]
 related_to:
   - "[[topic/trading]]"
   - "[[topic/algorithmic-trading]]"