fix(acp): deduplicate startup and record lifecycle notifications

[wgqqqqq]

Summary

• atomically claim ACP client startup so concurrent option and command requests share one connection
• replace the ACP session recovery overlay with ordinary notification-center history records for starting, success, and failure
• propagate the actual lifecycle outcome and remove the duplicate ACP error toast
• cover notification stack filtering and update startup performance selectors
• stabilize the multiline CLI PTY contract by using a sentinel that Ratatui differential rendering emits contiguously

Verification

• cargo test --locked -p bitfun-cli -p bitfun-acp -p bitfun-agent-runtime
• cargo check --workspace
• pnpm run type-check:web
• pnpm --dir src/web-ui run test:run src/shared/notification-system/components/NotificationContainer.test.tsx
• pnpm run i18n:audit
• git diff --check upstream/main...HEAD