### What problem does this PR solve?
Part of #15240 (rewriting the RAGFlow API server in Go).
Implements the two public bot endpoints from
`api/apps/restful_apis/bot_api.py`:
- **`GET /api/v1/chatbots/<dialog_id>/info`** (`chatbots_inputs`) —
returns `{title, avatar, prologue, has_tavily_key}` for a dialog the
authenticated tenant owns (tenant match + `status == VALID`), otherwise
`"Authentication error: no access to this chatbot!"`.
- **`GET /api/v1/searchbots/detail`** (`detail_share_embedded`) —
returns search-app detail for a `search_id` the tenant can access.
Permission is checked across the tenant's joined tenants; denial returns
`"Has no permission for this operation."` (operating error, `data:
false`) and a missing app returns `"Can't find this Search App!"`.
Both endpoints authenticate with an SDK **beta token** (`Authorization:
Bearer <beta>`) rather than a session — the token is resolved to a
tenant via `APIToken.query(beta=token)`, backed by a new
`APITokenDAO.GetByBeta`. Because they perform their own token-based
auth, the routes are registered on the unauthenticated route group
(mirroring the Python blueprint, which has no `@login_required`).
Both live in a new `internal/handler/bot.go` + `internal/service/bot.go`
since they share the same source module. Handler unit tests cover the
auth, success, and error-mapping paths.
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
---------
Co-authored-by: Claude Code <claude@anthropic.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-authored-by: Ling Qin <qinling0210@163.com>
## Summary
- add public Go route for `/api/v1/searchbots/detail`
- implement beta-token auth flow for shared search access
- add tenant-based access check for shared search apps
- add joined search detail query for the share response
- align Go response shape with the current Python runtime behavior
- add DAO / service / handler tests for the new endpoint
