Initial global Obsidian config

Shared config extracted from obsidian-config; vault-specific files (bookmarks.json, daily-notes.json) excluded.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Claude-Session: https://claude.ai/code/session_01ASYabtTgxSxJPjxPmBK9PJ

appearance.json

@@ -0,0 +1,8 @@
+{
+  "cssTheme": "Minimal",
+  "showRibbon": true,
+  "textFontFamily": "",
+  "translucency": true,
+  "interfaceFontFamily": "",
+  "baseFontSize": 18
+}