docs: standardize ecosystem hub reference to canonical blockquote

Aligns with the satellite format used across the LUMOS org. Replaces inline "Ecosystem: / For ecosystem context:" lines with the canonical `> **Ecosystem Context:**` blockquote.

Author: rz1989s

CLAUDE.md

@@ -1,8 +1,9 @@
 # CLAUDE.md - tree-sitter-lumos
 
+> **Ecosystem Context:** See [getlumos/lumos/CLAUDE.md](https://github.com/getlumos/lumos/blob/main/CLAUDE.md) for LUMOS ecosystem overview, cross-repo standards, and shared guidelines.
+
 **Repository:** https://github.com/getlumos/tree-sitter-lumos
-**Ecosystem:** Part of LUMOS language tooling
-**For ecosystem context:** See [lumos/CLAUDE.md](https://github.com/getlumos/lumos/blob/main/CLAUDE.md)
+**Purpose:** Tree-sitter grammar for LUMOS schema language
 
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