feat(buffer): add Buffer integration with posts, channels, and ideas (#5637)

* feat(buffer): add Buffer integration with posts, channels, and ideas

* fix(buffer): return clear tool error when account lookup yields no account

* fix(buffer): default schedulingType server-side so basic-mode blocks never fail validation

* fix(buffer): probe Content-Type for extensionless media URLs so videos are not sent as images

* feat(buffer): add get_ideas and get_idea_groups tools, harden media URL classification

* fix(buffer): guard missing post on PostActionSuccess responses

scripts/check-api-validation-contracts.ts

@@ -9,8 +9,8 @@ const QUERY_HOOKS_DIR = path.join(ROOT, 'apps/sim/hooks/queries')
 const SELECTOR_HOOKS_DIR = path.join(ROOT, 'apps/sim/hooks/selectors')
 
 const BASELINE = {
-  totalRoutes: 947,
-  zodRoutes: 947,
+  totalRoutes: 949,
+  zodRoutes: 949,
   nonZodRoutes: 0,
 } as const