feat: add Slack + Discord tool packages and fix 50 skipped sync packages

Add @tpmjs/tools-slack (10 tools) and @tpmjs/tools-discord (15 tools)
with full API coverage, typed outputs, and domain-validated blocks.

Add 7 missing business categories (finance, legal, hr, marketing, cx,
edu, sales) to TPMJS_CATEGORIES so 50 previously skipped packages
can sync to tpmjs.com.

Fix lefthook secrets hook to skip gracefully when git-secrets is not
installed.

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

packages/types/src/tpmjs.ts

@@ -30,6 +30,14 @@ export const TPMJS_CATEGORIES = [
   'automation',
   'ai-ml',
   'monitoring',
+  // Business categories
+  'finance',
+  'legal',
+  'hr',
+  'marketing',
+  'cx',
+  'edu',
+  'sales',
   // Aliases
   'doc',
   'text',