feat: add read-only /api/projects endpoint for external tools

Returns project tags from tag-manager (category=project).
Supports search (?q=), company filter (?company=), single by ID (?id=).
Same Bearer token auth as address-book API.

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

src/middleware.ts

@@ -46,6 +46,6 @@ export const config = {
      * - /favicon.ico, /robots.txt, /sitemap.xml
      * - Files with extensions (images, fonts, etc.)
      */
-    "/((?!api/auth|api/notifications/digest|api/compress-pdf|api/address-book|auth/signin|_next|favicon\\.ico|robots\\.txt|sitemap\\.xml|.*\\..*).*)",
+    "/((?!api/auth|api/notifications/digest|api/compress-pdf|api/address-book|api/projects|auth/signin|_next|favicon\\.ico|robots\\.txt|sitemap\\.xml|.*\\..*).*)",
   ],
 };