docs: add CurseForge API key to integrations doc

docs/integrations/claude-connectors.md

@@ -262,6 +262,33 @@ curl -u "mkrause612:TOKEN" -X MKCOL \
   "https://downloads.firefrostgaming.com/remote.php/dav/files/mkrause612/NewFolder/"
 ```
 
+---
+
+## CurseForge API
+
+**Purpose:** Authenticated mod/modpack downloads and metadata lookup
+**API Key:** `$2a$10$OVK9ml7bEJdcfTJhBSuK1O5AFz2qq3mwpb35RTTwVfmdvzOFOA7M.`
+**Approved:** April 2, 2026 — Application: Firefrost Modpack Version Checker
+**Docs:** https://docs.curseforge.com/#getting-started
+
+```bash
+# Get mod info
+curl -s -H "x-api-key: KEY" "https://api.curseforge.com/v1/mods/{projectId}"
+
+# Get file download URL
+curl -s -H "x-api-key: KEY" "https://api.curseforge.com/v1/mods/{projectId}/files/{fileId}/download-url"
+
+# List files for a modpack (filter by MC version)
+curl -s -H "x-api-key: KEY" "https://api.curseforge.com/v1/mods/{projectId}/files?gameVersion=1.21.1"
+```
+
+**Notes:**
+- Some mod authors block 3rd-party API downloads (403) — cosmetic/client mods mostly
+- Used by ModpackChecker for version detection
+- Used by AI-powered modpack installer (Task #101) for authenticated pack downloads
+
+---
+
 **Current Structure:**
 ```
 Firefrost-Mods/