refactor: P0-P3 fixes, C1 cleanup, architecture diagrams, go.work upgrade

- P0-1: ProviderError type + ReportStatus for precise 401/403 detection
- P0-2: Remove -config flag from deploy/homeagent.service
- P2-1: 5s debounce on context.go Save()
- P2-2→C1: Delete output_set_channel entirely
- P2-3: Extract mediaDataURL/mediaChat helpers
- P2-4: Dedup defaultSources var
- P3: Delete dead packages (embed/tokenizer/container/snapshot)
- P3: Delete dead functions (messagesToMap, RunStageAll)
- CL: Update .gitignore, docs, Makefile, gojieba removal
- Config: Delete config/config.yaml, update docs
- Arch: Remove EmitOutputTo from emitResponse
- CL-1: go.work 1.19→1.21
- Docs: Add Mermaid architecture diagrams to README
- Docs: Add kernel-rebuild requires plugin-rebuild note to PLUGIN_DEV.md

go.mod

@@ -3,11 +3,9 @@ module gitcode.com/JianFeeeee/HomeAgent
 go 1.19
 
 require (
-	gitcode.com/JianFeeeee/homeagent-sdk v0.0.0-20260706112739-e073074a267d
-	github.com/gorilla/websocket v1.5.3
 	github.com/mattn/go-sqlite3 v1.14.22
-	github.com/yanyiwu/gojieba v1.4.7
 	github.com/yuin/gopher-lua v1.1.2
 	gopkg.in/yaml.v3 v3.0.1
 )
 
+require gitcode.com/JianFeeeee/homeagent-sdk v0.0.0-20260708004841-e9bdcf9304b0 // direct