feat: support --set/--del on update trigger

docs/mutation.md

@@ -75,6 +75,7 @@ The difference between **omitted** and **explicitly written** matters for merge-
 ## File input, GET YAML, and current limits
 
 - If an endpoint accepts `-f`, supplying a file takes precedence over GET-then-update. The supplied body is sent as a write document (with the endpoint's file-body wrapping behavior); it is **not** run through the field handlers or the flag-built sparse PATCH path. `body_params` from the automatic mutation path are not merged into it. A full write-ready PATCH file is allowed, but inspect its shape before sending it.
+- When the API stores the resource as a YAML string inside a JSON response (for example `data.yaml` on triggers), pick it with `update_body_pick: yamlParse(it.data.yaml)` and set `content_type: application/yaml`. The mutated object is then re-encoded as the YAML request body, so comments are dropped and keys are written sorted.
 - `get --format yaml` still uses the **get command's separate `yaml_pick_expr` / `yaml_exclude`**, not `update_body_pick` or custom field handlers. FME's current YAML output is not automatically write-ready for tags/owners; do not promise a GET-YAML-to-`-f` round trip until its specs and conversion path are addressed.
 - There is no `patch_always_fields` facility yet. PATCH does not copy unchanged picked IDs or other required fields automatically. If an API requires one, establish that requirement before changing the spec/core; an explicit `body_params` value may suffice when it is available independently of GET.
 - Core does not look up owner emails or reconstruct missing API identifiers. FME currently returns a group name without the identifier needed to write that group back; that requires a server-side round-trip fix before mixed-owner edits can be reliable.

modules/pipeline/pipeline.go

@@ -17,8 +17,6 @@ import (
 func ModuleInit(reg registry.ModuleRegistrar) {
 	reg.RegisterFetchFn(listExecutionLogsFetchFnID, listExecutionLogsFetchFn)
 	reg.RegisterWorkflow(getPipelineLogHandlerID, getPipelineLogHandler)
-	reg.RegisterWorkflow(updateTriggerEnableHandlerID, updateTriggerEnableHandler)
-	reg.RegisterWorkflow(updateTriggerDisableHandlerID, updateTriggerDisableHandler)
 	reg.RegisterBodyFn(executePipelineBodyFnID, executePipelineBody)
 	reg.RegisterBodyFn(executeInputSetBodyFnID, executeInputSetBody)
 	reg.RegisterBodyFn(executeDynamicBodyFnID, executeDynamicBody)

pkg/exprenv/exprenv.go

@@ -62,6 +62,7 @@ func BaseFuncs(ptyEnabled bool) map[string]any {
 		"substr":                exprfuncs.Substr,
 		"formatOrder":           exprfuncs.FormatOrder,
 		"env":                   exprfuncs.Env,
+		"yamlParse":             exprfuncs.YamlParse,
 		"b64decode":             exprfuncs.Base64Decode,
 	}
 }