Slack's files.uploadV2 API no longer supports the filetype field and logs
deprecation warnings when it's included. Slack auto-detects the file type
from the file content, so this field is unnecessary.
This removes the warning:
[WARN] web-api:WebClient filetype is no longer a supported field in files.uploadV2.
The status bar refresh failed because refreshSessionInfo() compared
currentSessionKey (e.g. 'main') against the canonical session keys
returned by the gateway (e.g. 'agent:default:main').
This fix uses parseAgentSessionKey to also match canonical keys by
their 'rest' component, allowing 'main' to match 'agent:default:main'.
Fixes: status bar showing stale values after setting changes
AI-assisted: yes (Claude)
Testing: lightly tested (build passes, logic verified)
Jonathan Rhyne