refactor: remove core skill direct loading, skills owned by clawhubadapter only

- Drop skill.NewManager from homed bootstrap; skills dir no longer core-managed
- Remove GetInjectedPrompt system-prompt injection (skills are not first-class)
- Delete internal/skill package, SkillAPI, webui /api/v1/skills, status skills block
- ConfigRegistry: plugin config tables now created only via RegisterDef; arbitrary
  scope Set/Get no longer implicitly creates config_<name> tables (fixes stray
  config_today_task table from SKILL directory name being used as a scope)

internal/agent/core/agent.go

@@ -17,7 +17,6 @@ import (
 	"gitcode.com/JianFeeeee/HomeAgent/internal/memory/social"
 	"gitcode.com/JianFeeeee/HomeAgent/internal/memory/text"
 	"gitcode.com/JianFeeeee/HomeAgent/internal/plugin"
-	"gitcode.com/JianFeeeee/HomeAgent/internal/skill"
 	"gitcode.com/JianFeeeee/HomeAgent/internal/tracker"
 	"gitcode.com/JianFeeeee/HomeAgent/pkg/types"
 )
@@ -33,7 +32,6 @@ type Agent struct {
 	io              *agentIO.IOManager
 	memory          *memory.GraphDB
 	indexer         *memory.Indexer
-	skills          *skill.Manager
 	tracker         *tracker.Tracker
 	context         *RelevanceContext
 	systemPrompt    string
@@ -122,7 +120,6 @@ type AgentConfig struct {
 	IO              *agentIO.IOManager
 	Memory          *memory.GraphDB
 	Indexer         *memory.Indexer
-	Skills          *skill.Manager
 	Tracker         *tracker.Tracker
 
 	DocStore           *document.Store
@@ -190,7 +187,6 @@ func New(cfg AgentConfig) *Agent {
 		io:              cfg.IO,
 		memory:          cfg.Memory,
 		indexer:         cfg.Indexer,
-		skills:          cfg.Skills,
 		tracker:         cfg.Tracker,
 		context:         rc,
 		systemPrompt:    cfg.SystemPrompt,