Support task IDs with chat --resume

[temp-deepshard]

Summary

Extend the existing truffile chat --resume flag to accept an optional task ID, and make recent-task selection consistently use the most recently updated chats.

This keeps one chat command instead of adding parallel run or resume commands. The existing chat engine, task streams, picker, one-shot path, and compatibility flags remain in place.

Behavior

truffile chat                               # interactive new chat
truffile chat "summarize this" --json       # existing one-shot chat
truffile chat --resume                      # interactive recent-task picker
truffile chat --resume TASK_ID              # reopen this task interactively
truffile chat --resume TASK_ID "follow up"  # continue this task one-shot
truffile chat --resume-last "follow up"     # continue the most recently updated task

--task-id remains supported for compatibility. Supplying conflicting IDs through --resume and --task-id fails during argument parsing.

Implementation

• let the existing chat --resume parser accept an optional task ID
• normalize that ID onto the existing task_id field consumed by the chat engine
• keep exact-ID resume interactive when attached to a TTY with no prompt
• reuse the existing one-shot continuation path when a prompt, stdin, prompt file, or JSON output is requested
• let the existing interactive resume block open either the selected picker task or an exact task ID
• normalize the task-info response to newest-updated first and exactly the requested count
• ignore *.whl so local build artifacts cannot be staged accidentally

The ordering normalization is necessary because the device returns max_before + 1 records in oldest-to-newest order. Without it, --resume-last could select an older task, the picker opened on the oldest visible task, and --list-tasks N returned N+1 rows.

No wheel, generated protobuf, copied runtime, packaging configuration, or unrelated CLI files are included.

Validation

• focused resume and task-history tests: 8 passed
• full suite: 161 passed, 1 subtests passed
• Ruff passes for the changed tests and critical-error rules pass for all touched Python modules
• git diff --check passes
• built the exact branch as a wheel outside the repository and installed it into a fresh virtual environment
• installed-wheel help documents chat --resume [TASK_ID]
• physical truffle-6239 continuity test:
  • created disposable chats A and B with distinct context tokens
  • chat --list-tasks 1 --json returned exactly B as the newest task
  • chat --resume-last reused B's task ID and recovered B's context token
  • interactive chat --resume A_TASK_ID reopened A and recovered A's context token after a live follow-up
  • chat --resume placed the most recently updated task first in the picker
  • both disposable tasks were deleted and verified absent