Workflow creation doesn't work

[ritheeshbs]

Describe the bug
Workflow creation closes the dialog, but the workflows page stays empty

Buzz Desktop version: v0.5.5
Relay:
wss://dunsocial.communities.buzz.xyz

Steps:

1. Open Workflows.
2. Click Create Workflow.
3. Fill required fields.
4. Add a Send Message step.
5. Click Create.

Expected:
Workflow appears in the Workflows list.

Actual:
Dialog closes successfully.
Workflows page remains empty.
Restarting Buzz does not make the workflow appear.
No error message is shown.

[yippietheproducer]

Root cause found and fixed — PR #5049.

What was wrong (server-side, live-reproduced): the HTTP bridge collapsed a multi-value #h filter to its FIRST channel. The desktop Workflows overview sends one batched query {"kinds":[30620], "#h":[c1, c2, ...]} across all member channels. extract_channel_id_from_filter returned the first parseable UUID regardless of count, so the SQL intersected channel_id = <first> with the caller's full access scope — matching only the first channel. When that channel (often a DM, lexicographically first) had no workflows, the page returned empty with no error. Creation itself always succeeded, which is why the dialog closed cleanly.

Verified live against a running relay: the batched query returned [] before the fix and both stored workflows after. Single-channel and #d queries were unaffected.

This also explains #4419 (same root cause; the reporters there described the lexicographic-first-channel collapse exactly). After this fix lands, the Workflows overview will list workflows from every member channel.