Update the HTTP client module and web UI to work with the unified agentd API.
Changes to Omni/Agents/Client.hs:
1. Remove deleteWorktree function (endpoint deleted)
2. Remove mergeAgent function if it depends on worktrees
3. Update spawnAgent to use new SpawnRequest format (cwd instead of workspace/repo)
4. Ensure listAgents, getAgent, sendMessage, stopAgent still work with updated response format
5. Update AgentInfo type if fields changed (remove worktree-related fields)
Changes to Omni/Agents/Web.hs: 1. Remove worktree management UI 2. Update agent spawn form to use CWD instead of repo/workspace 3. Update status display for systemd-based state
The client module is used by Ava's tools and the web interface. Both need to work after the daemon refactor.
Files to modify:
Ava verified: implementation present in live tree (file/feature confirmed via inspection). Moving to Verified.
Updated Omni.Agents client/web flows for unified API (cwd + thinking in spawn, remove endpoint replaces merge/discard actions). Updated Ava call sites to send canonical cwd and to remove agents via DELETE /agents/:id (with stop fallback in orchestrator cleanup).