release: v1.2.0 — community-ready, full docs, PDF guide

Critical fixes:
- marketplace.json: fix version 1.0.0→1.2.0, fix email to ***REMOVED***
- main.canvas: remove 5 broken file references (gitignored files)
- community-plugins.json: deduplicate from 6→4 canonical entries

Vault onboarding:
- wiki/getting-started.md: new onboarding page inside the vault
- wiki/index.md: populate Entities, Sources, Questions, Comparisons sections
- wiki/meta/dashboard.md: fix Dataview queries (was referencing non-existent fields)
- welcome.canvas: add CTA node pointing to getting-started
- CLAUDE.md: replace placeholder text with actual vault description

Docs:
- README.md: complete Plugins section (pre-installed + recommended), CSS Snippets section, Banner usage section, file structure updated
- bin/setup-vault.sh: expanded success message listing all plugins and CSS snippets
- docs/install-guide.md + docs/install-guide.pdf: printable community install guide

Version: 1.1.0 → 1.2.0

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "cosmic-brain",
-  "version": "1.1.0",
+  "version": "1.2.0",
   "description": "Claude + Obsidian knowledge companion. Sets up a persistent, compounding wiki vault. Covers memory management, session notetaking, knowledge organization, and agent context across projects. Based on Andrej Karpathy's LLM Wiki pattern.",
   "author": {
     "name": "AgriciDaniel",