chore: reorganize into polyglot monorepo (workshop)

- Move bigmind/ -> mcp/bigmind/
- Move webscraper/ -> mcp/webscraper/
- Move mss-failsafe/ -> java/mss-failsafe/
- Move Wellmann-Shop/ -> java/wellmann-shop/ (normalize to kebab-case)
- Add .roo/ IDE config files to tracking
- Add plans/REPO_STRATEGY.md (monorepo strategy document)
- Expand .gitignore: Java/Maven, Node/TS, coverage, uv.lock
- Rewrite README.md as navigation index
- Update .roo/mcp.json webscraper path to mcp/webscraper/

.gitignore

@@ -1,4 +1,4 @@
-# Python
+# ── Python ────────────────────────────────────────────────────────────────────
 __pycache__/
 *.py[cod]
 *$py.class
@@ -31,19 +31,44 @@ ENV/
 env.bak/
 venv.bak/
 
-# IDE
+# uv
+uv.lock
+
+# Coverage
+.coverage
+coverage.xml
+htmlcov/
+
+# ── Java / Maven ──────────────────────────────────────────────────────────────
+target/
+*.class
+*.war
+*.jar
+*.ear
+*.nar
+.classpath
+.project
+.settings/
+*.iml
+
+# ── Node / TypeScript (future) ────────────────────────────────────────────────
+node_modules/
+dist/
+*.js.map
+
+# ── IDE ───────────────────────────────────────────────────────────────────────
 .vscode/
 .idea/
 *.swp
 *.swo
 
-# OS
+# ── OS ────────────────────────────────────────────────────────────────────────
 .DS_Store
 Thumbs.db
 
-# Databases
+# ── Databases ─────────────────────────────────────────────────────────────────
 *.db
 *.sqlite3
 
-# Logs
-*.log
+# ── Logs ──────────────────────────────────────────────────────────────────────
+*.log