feat(im): Add user-owned IM channel connections (#3487)

* Add user-owned IM channel connections

* Fix dev startup and channel connect popup

* Use async channel connect flow

* Harden dev service daemon startup

* Support local IM channel connections

* Align IM connections with local channels

* Fix safe user id digest algorithm

* Address Copilot IM channel feedback

* Address IM channel review comments

* Support all integrated IM channel connections

* Format additional channel connection tests

* Keep unavailable channel connect buttons clickable

* Fix IM channel provider icons

* Add runtime setup for enabled IM channels

* Guard global shortcut key handling

* Keep configured IM channels editable

* Avoid password autofill for channel secrets

* Make channel threads visible to connection owners

* Persist IM runtime config locally

* Allow disconnecting runtime IM channels

* Route no-auth channel sessions to local user

* Use default user for auth-disabled local mode

* Show IM channel source on threads

* Prefill IM channel runtime config

* Reflect IM channel runtime health

* Ignore Feishu message read events

* Ignore Feishu non-content message events

* Let setup wizard enable IM channels

* Fix frontend formatting after merge

* Stabilize backend tests without local config

* Isolate channel runtime config tests

* Address channel connection review comments

* Use sha256 user buckets with legacy migration

* Ensure runtime IM channels are ready after restart

* Persist disconnected IM channel state

* Address channel connection review comments

* Address channel connection review findings

Frontend connect flow:
- Open the runtime-config dialog only when a provider still needs
  credentials; configured providers go straight to the connect flow, so
  the binding-code/deep-link path is reachable from the UI again.
- After saving credentials, continue into the connect flow when a user
  binding is still required (multi-user mode) instead of stopping at a
  "Connected" toast.
- Extract shared provider-state helpers to core/channels/provider-state
  and add unit + e2e coverage for the direct-connect and
  configure-then-connect paths.

Provider status semantics:
- Report connection_status from the user's newest connection row;
  with no binding it is not_connected, except in auth-disabled local
  mode where a configured running channel is effectively connected.

Concurrency and event-loop correctness:
- Offload ChannelRuntimeConfigStore construction and writes, channel
  service construction, and Slack connection replies to threads; add a
  tests/blocking_io/ anchor for the runtime-config handlers.
- Consume binding codes with a conditional UPDATE so a code can only be
  used once under concurrent workers; retry upsert_connection as an
  update when a concurrent insert wins the unique constraint.
- Serialize ensure_channel_ready per channel so concurrent provider
  polls cannot double-start a channel worker.

Config and migration hardening:
- Stop mutating the get_app_config()-cached Telegram provider config;
  the runtime store now owns the UI-entered bot username.
- Register channel_connections in STARTUP_ONLY_FIELDS with the
  standardized startup-only Field description.
- Match the legacy unsafe-id bucket by recomputing its exact SHA-1 name
  so another user's same-prefix bucket can never be migrated.
- Remove the unused Telegram process_webhook_update path and document
  src/core/channels in the frontend docs.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Address PR review comments on authz scoping and channel runtime

Security (review feedback from ShenAC-SAC):
- Scope internal-token callers to the connection owner carried in
  X-DeerFlow-Owner-User-Id instead of bypassing owner checks outright,
  in both require_permission(owner_check=True) and the stateless run
  endpoints. Internal callers keep access to their own and
  shared/legacy threads, and may claim a default-owned channel thread
  for its real owner, but a leaked internal token no longer grants
  cross-user thread access.
- Require admin privileges for POST/DELETE /api/channels/{provider}/
  runtime-config: runtime credentials and channel workers are
  instance-wide shared state (same model as the MCP config API).
  Read-only provider listing stays available to all users.

Performance (review feedback from willem-bd):
- Skip the redundant thread channel-metadata PATCH after the first
  successful backfill per thread.
- Reuse the per-connection Slack WebClient until its token changes
  instead of constructing one per outbound message.
- Reconcile channel readiness for all providers concurrently in
  GET /api/channels/providers.

Also resolve the code-quality unused-import flag in the blocking-io
anchor by pre-importing the channel service via importlib.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Fix prettier formatting in provider-state test

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Reconcile UI runtime channel config with config reload on restart

Main now reloads a channel's config.yaml entry on restart_channel()
(#3514, issue #3497). Adapt the user-owned connection flow to coexist:

- configure_channel() restarts with reload_config=False — the caller
  just supplied the authoritative config (browser-entered credentials
  that are never written to config.yaml), so a file reload must not
  clobber it with the stale on-disk entry.
- _load_channel_config() re-applies the UI runtime-store overlay used
  at startup, so an operator-triggered restart keeps browser-entered
  credentials for channels without a config.yaml entry and does not
  resurrect a channel disconnected from the UI.
- Offload the reload's disk IO (config.yaml + runtime store) with
  asyncio.to_thread, matching the blocking-IO policy on this branch.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

backend/app/channels/message_bus.py

@@ -44,6 +44,12 @@ class InboundMessage:
             Messages sharing the same ``topic_id`` within a ``chat_id`` will
             reuse the same DeerFlow thread.  When ``None``, each message
             creates a new thread (one-shot Q&A).
+        connection_id: Optional DeerFlow channel connection id. When present,
+            conversation mapping is scoped by the connection instead of the
+            legacy global ``channel_name:chat_id[:topic_id]`` key.
+        owner_user_id: DeerFlow user id that owns the channel connection.
+            Platform user ids stay in ``user_id``.
+        workspace_id: Optional external workspace/guild/team id.
         files: Optional list of file attachments (platform-specific dicts).
         metadata: Arbitrary extra data from the channel.
         created_at: Unix timestamp when the message was created.
@@ -56,6 +62,9 @@ class InboundMessage:
     msg_type: InboundMessageType = InboundMessageType.CHAT
     thread_ts: str | None = None
     topic_id: str | None = None
+    connection_id: str | None = None
+    owner_user_id: str | None = None
+    workspace_id: str | None = None
     files: list[dict[str, Any]] = field(default_factory=list)
     metadata: dict[str, Any] = field(default_factory=dict)
     created_at: float = field(default_factory=time.time)
@@ -95,6 +104,9 @@ class OutboundMessage:
         is_final: Whether this is the final message in the response stream.
         thread_ts: Optional platform thread identifier for threaded replies.
         metadata: Arbitrary extra data.
+        connection_id: Optional DeerFlow channel connection id used for
+            connection-specific outbound credentials.
+        owner_user_id: DeerFlow user id that owns the channel connection.
         created_at: Unix timestamp.
     """
 
@@ -106,6 +118,8 @@ class OutboundMessage:
     attachments: list[ResolvedAttachment] = field(default_factory=list)
     is_final: bool = True
     thread_ts: str | None = None
+    connection_id: str | None = None
+    owner_user_id: str | None = None
     metadata: dict[str, Any] = field(default_factory=dict)
     created_at: float = field(default_factory=time.time)