**Category:** fix
**User Impact:** Editing a channel message now opens in the main
composer, while editing a thread reply stays in the thread composer,
with focus ready for typing.
**Problem:** When a thread was open, Buzz treated its root message as
thread-owned and opened edits in the thread composer. Menu-driven edits
also lacked regression coverage for immediate focus.
**Solution:** Carry the message's semantic root/reply classification
into the edit target, route only actual replies to the thread composer,
and use the menu primitive's selection event for a reliable handoff.
End-to-end tests cover placement and focus for both paths.
<details>
<summary>File changes</summary>
**desktop/src/features/channels/ui/ChannelPane.tsx**
Routes edit targets by semantic thread ownership rather than membership
in the open thread panel.
**desktop/src/features/channels/ui/ChannelPane.types.ts**
Uses the shared composer edit-target type so routing metadata stays
attached to the target.
**desktop/src/features/messages/lib/draftMentionRefs.ts**
Classifies each edit target as a root or true thread reply from its
event tags.
**desktop/src/features/messages/lib/draftMentionRefs.test.mjs**
Covers semantic ownership for root and reply edit targets.
**desktop/src/features/messages/ui/MessageActionBar.tsx**
Handles Edit through the dropdown menu's selection event so focus
restoration and edit startup share the intended lifecycle.
**desktop/src/features/messages/ui/MessageComposer.types.ts**
Adds semantic thread ownership to the edit-target contract.
**desktop/tests/e2e/messaging.spec.ts**
Verifies root edits use and focus the main composer, while reply edits
use and focus the thread composer.
</details>
### Reproduction Steps
1. Send a channel message and open its thread.
2. From the thread panel, edit the root message; confirm its content
loads in the main composer and the editor is focused.
3. Send a reply in that thread.
4. Edit the reply; confirm its content loads in the thread composer and
the editor is focused.
### Screenshots
**Editing a channel-root message uses the main composer**
**Editing an actual thread reply uses the thread composer**
---------
Signed-off-by: Taylor Ho <taylorkmho@gmail.com>
Co-authored-by: Rizz <302abe414ca6e3134763d2539bfcf145aea2a63fe5f8455204ed602fd40cf381@buzz.block.builderlab.xyz>
Co-authored-by: Carl <acda9e433d19dcd0e6b6840f7f4b98f3a56f1fab98049d444c087019e6d36560@buzz.block.builderlab.xyz>
4bf80978f5
