### Summary
As title
- [x] fix tool & component `Retrieval KB`
- [x] fix agent cannot use `Retrieval KB` in agent chat
#### Main cause
Model provider do not set up:
```Go
if chatModelConfig.Tools != nil {
reqBody["tools"] = chatModelConfig.Tools
}
```
#### Working Now
<img width="3774" height="2128" alt="image"
src="https://github.com/user-attachments/assets/400a349d-0211-43e5-a7ec-7a014acf77a6"
/>
```
____________________________________
< This PR takes me all day to do it. >
------------------------------------
\
\ (\__/)
(•ㅅ•)
/ づ
```
Replaces the Python agent canvas runtime with a Go implementation that
runs inside `cmd/server_main`.
The canvas compiles into an eino Workflow that pauses on wait-for-user
via native Interrupt/Resume (no sentinel flag) and resumes from a
Redis-backed CheckPointStore.
All 21 Python agent components and ~35 tools are ported with functional
parity.
Sandbox providers now read their JSON config from the admin-panel
system_settings table with env fallback.
234 files / +35,413 / -6,111. All Go files are gofmt-clean (CI gate
added); drops the v2 DSL E2E step and the gap-analysis plan (both
redundant after the port ships).
## Type of change
- [x] Refactoring
- [x] New feature
- [x] Bug fix
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude <noreply@anthropic.com>
