feat: add D.intelligence Agent Corps (9 skills + shared infra)

Add 9 agent skills (#70-#77, #88) for D.intelligence business operations:
brand guardian, brand editor, doc secretary, quotation manager, service
architect, marketing manager, back office manager, account manager, and
skill update meta-agent. Includes shared Python package (dintel), reference
docs, document/quotation templates, service module CSVs, cross-device
installer, and comprehensive user guide.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -85,6 +85,17 @@ token.json
 .claude/*
 !.claude/commands/
 
+# Claude Code agent workspace
+.claude-agents/
+
+# Node lock files
+package-lock.json
+
+# Egg info / build artifacts
+*.egg-info/
+dist/
+build/
+
 # Temporary files
 output/
 keyword_analysis_*.json