v0.1.1 - Remove dsh-web dependency

The timer-agent plugin now works correctly without dsh-web plugin installed.

Changes

• Add fallback selectors for finding conversation column: [data-pane=conversation], [class*=centerCol]\
• Add fallback for sessions service when unavailable (noop implementation)
• Add fallback for ctx.effect when unavailable (check existence before calling)
• Add fallback in target-options.sessionRows when sessions service missing
• Update CSS to support [class*=centerCol]\ positioning context

This ensures the timer-agent UI panel works in various DSH deployments where the exact DOM structure or available services may vary.