Fix collaborative_editor_url incorrectly mapping trigger/edge s param to job

[m4cd4r4]

Summary

Closes #4375

When a user switches from the legacy editor to the collaborative editor,
the s query param (selected node) is converted to the appropriate collab
param (job=, trigger=, or edge=). The conversion depends on
determine_selection_type/2, which pattern-matches on atom-keyed socket
assigns (selected_trigger, selected_job, selected_edge).

The bug: collaborative_editor_url/2 was passing the URL params map
(string-keyed) as the 4th argument to convert_param, not socket assigns.
Since the URL params never contain :selected_trigger etc., the cond always
fell through to the default "job" case - so triggers and edges were always
mapped to job= instead of trigger= or edge=.

Changes

• collaborative_editor_url/3 now takes an optional assigns arg (defaults
  to %{} for backward compat) and passes it to convert_param instead of
  the URL params map
• edit.ex now passes socket.assigns when calling collaborative_editor_url
  from the switch_to_collab_editor event handler
• Three new tests cover the fixed trigger/edge/job resolution with assigns

Checklist

• I have added tests to cover my changes
• I have used an AI assistant (Claude Code) to help produce this code

[m4cd4r4]

The test_elixir failure is a pre-existing flaky test (sorting workflows by last_workorder_updated_at desc) unrelated to this change - it touches no workflow sorting code. The lint failure has been fixed in the latest push (line too long in edit.ex).