docs: add docker-language-server validation and update documentation

Document docker-language-server LSP build and validation success.

Changes:
- STATUS.md: Added docker-language-server as validated LSP (v0.0.0, 49.2MB)
- AGENTS.md: Moved docker-language-server to Development Tools section
- AGENTS.md: Updated server counts (Development Tools: 2→3, Additional Tools: 3→2)
- AGENTS.md: Added No Language/Prebuilt category for LSP servers

Validation:
- Container builds successfully from custom multi-stage Dockerfile
- Version 0.0.0 verified with --version flag
- Crush wrapper script functional
- User acceptance testing completed in fresh Crush session

STATUS.md

@@ -20,6 +20,7 @@ Last validated: 2026-01-22
 
 **Recently Built:**
 - bash-language-server: Built (v5.6.0) - configured in crush.json via wrapper script
+- docker-language-server: Built (v0.0.0) - configured in crush.json via wrapper script
 
 **Builds in Progress:**
 - None
@@ -29,12 +30,14 @@ Last validated: 2026-01-22
 
 **LSP Servers:**
 - ✓ bash-language-server: Working (v5.6.0) - stdio-based, configured in crush.json
+- ✓ docker-language-server: Working (v0.0.0) - stdio-based, configured in crush.json
 
 ## Detailed Status
 
 | Repository | Status | Notes |
 |------------|--------|-------|
 | bash-language-server | Built | Container built using prebuilt npm package (190MB). LSP configured in crush.json via wrapper script. Version 5.6.0. |
+| docker-language-server | Built | Container built from Go source (49.2MB). LSP configured in crush.json via wrapper script. Version 0.0.0. |
 
 ## Known Issues