fix(background): Wave 2 - fix interrupt status checks, display text, error recovery grace, LSP JSONC

- fix(background): include "interrupt" status in all terminal status checks (3 files)
- fix(background): display "INTERRUPTED" instead of "CANCELLED" for interrupted tasks
- fix(cli): add error recovery grace period in poll-for-completion
- fix(lsp): use JSONC parser for config loading to support comments

All changes verified with tests and typecheck.

src/tools/call-omo-agent/background-agent-executor.ts

@@ -48,7 +48,7 @@ export async function executeBackgroundAgent(
 				return `Task aborted while waiting for session to start.\n\nTask ID: ${task.id}`
 			}
 			const updated = manager.getTask(task.id)
-			if (updated?.status === "error" || updated?.status === "cancelled") {
+			if (updated?.status === "error" || updated?.status === "cancelled" || updated?.status === "interrupt") {
 				return `Task failed to start (status: ${updated.status}).\n\nTask ID: ${task.id}`
 			}
 			await new Promise<void>((resolve) => {