Bring the channel-aware Stream linking ("建联") from PR #407 into the devapp
command tree as `dws devapp robot connect`, so the full lifecycle
(create app -> create robot -> link to a local agent) lives under one
`dws devapp` domain instead of a separate `dws connect` command.
- Reuse, not duplicate: provisioning ("建号") stays on devapp's existing
`robot create/submit/result`; this commit ports only the linking half.
- connect_stream.go: the Go-native in-process Stream forwarder + channel
agent registry, ported verbatim from #407 (package helpers, self-contained).
- devapp_connect.go: trimmed channel routing (resolveConnectChannel /
launchConnector / buildConnectPlan / ...) plus the new subcommand. The
standalone `connect` cobra command, `connect start` and `connect bot create`
are intentionally NOT brought over — the capability is consolidated under
`dws devapp robot`.
- Credentials: `--robot-client-id` / `--robot-client-secret` for an existing
robot, or `--unified-app-id` to auto-fetch via devapp's credentials get.
The flags are named `robot-client-*` (not `client-id`/`client-secret`) to
avoid shadowing the global OAuth client-override persistent flags.
- Adds the dingtalk-stream-sdk-go v0.9.1 dependency.
- Skill docs (devapp.md, robot.md mono+multi) document `robot connect`.
Known follow-up (marked in code + docs): the get_open_dev_app_credentials
response field names used by `--unified-app-id` auto-fetch are not yet
confirmed against the real gateway; the path degrades safely (empty -> fall
back to explicit flags) and must be verified against pre-prod before relying
on it.
修雨