Convert all schemas to flat format with inline required/secret

All schemas (parameters, output, output_schema, conf_schema) now use the
StackStorm-style flat format expected by Attune:
  { param_name: { type, description, required, secret, ... } }

Instead of the standard JSON Schema format:
  { type: object, properties: { ... }, required: [...] }

Also fix rule template syntax: trigger.payload.* -> event.payload.*

rules/count_and_log.yaml

@@ -2,7 +2,7 @@
 # Connects the counter sensor trigger to the read_counter action
 #
 # When the counter sensor fires, this rule passes the counter value
-# and rule reference from the trigger payload into the read_counter action.
+# and rule reference from the event payload into the read_counter action.
 
 ref: nodejs_example.count_and_log
 pack_ref: nodejs_example
@@ -13,10 +13,10 @@ description: "Fires on each counter tick and logs the current counter value"
 trigger_ref: nodejs_example.counter
 action_ref: nodejs_example.read_counter
 
-# Map trigger payload fields into action parameters
+# Map event payload fields into action parameters
 action_params:
-  counter: "{{ trigger.payload.counter }}"
-  rule_ref: "{{ trigger.payload.rule_ref }}"
+  counter: "{{ event.payload.counter }}"
+  rule_ref: "{{ event.payload.rule_ref }}"
 
 # No conditions — fire on every counter event
 conditions: {}