Add customizable plugin display names and weights (#8459)

* feat: add customizable plugin display names and weights

- Add weight field to JobTypeCapability proto message
- Modify ListKnownJobTypes() to return JobTypeInfo with display names and weights
- Modify ListPluginJobTypes() to return JobTypeInfo instead of string
- Sort plugins by weight (descending) then alphabetically
- Update admin API to return enriched job type metadata
- Update plugin UI template to display names instead of IDs
- Consolidate API by reusing existing function names instead of suffixed variants

* perf: optimize plugin job type capability lookup and add null-safe parsing

- Pre-calculate job type capabilities in a map to reduce O(n*m) nested loops
  to O(n+m) lookup time in ListKnownJobTypes()
- Add parseJobTypeItem() helper function for null-safe job type item parsing
- Refactor plugin.templ to use parseJobTypeItem() in all job type access points
  (hasJobType, applyInitialNavigation, ensureActiveNavigation, renderTopTabs)
- Deterministic capability resolution by using first worker's capability

* templ

* refactor: use parseJobTypeItem helper consistently in plugin.templ

Replace duplicated job type extraction logic at line 1296-1298 with
parseJobTypeItem() helper function for consistency and maintainability.

* improve: prefer richer capability metadata and add null-safety checks

- Improve capability selection in ListKnownJobTypes() to prefer capabilities
  with non-empty DisplayName and higher Weight across all workers instead of
  first-wins approach. Handles mixed-version clusters better.
- Add defensive null checks in renderJobTypeSummary() to safely access
  parseJobTypeItem() result before property access
- Ensures malformed or missing entries won't break the rendering pipeline

* fix: preserve existing DisplayName when merging capabilities

Fix capability merge logic to respect existing DisplayName values:
- If existing has DisplayName but candidate doesn't, preserve existing
- If existing doesn't have DisplayName but candidate does, use candidate
- Only use Weight comparison if DisplayName status is equal
- Prevents higher-weight capabilities with empty DisplayName from
  overriding capabilities with non-empty DisplayName

weed/admin/plugin/plugin_scheduler.go

@@ -175,7 +175,8 @@ func (r *Plugin) ListSchedulerStates() ([]SchedulerJobTypeState, error) {
 	r.schedulerMu.Unlock()
 
 	states := make([]SchedulerJobTypeState, 0, len(jobTypes))
-	for _, jobType := range jobTypes {
+	for _, jobTypeInfo := range jobTypes {
+		jobType := jobTypeInfo.JobType
 		state := SchedulerJobTypeState{
 			JobType:           jobType,
 			DetectionInFlight: detectionInFlight[jobType],
@@ -187,6 +188,7 @@ func (r *Plugin) ListSchedulerStates() ([]SchedulerJobTypeState, error) {
 		}
 
 		policy, enabled, loadErr := r.loadSchedulerPolicy(jobType)
+
 		if loadErr != nil {
 			state.PolicyError = loadErr.Error()
 		} else {