quickstart.sh crashes on unset $TERM, and hides the real error on workspace install failure

Description

Two related bugs in quickstart.sh:

1. Line 96 (and 2317) call clear unconditionally under set -e (line 12). If $TERM is unset in the shell (happens in some IDE terminals, CI, non-interactive shells), clear exits 1 and set -e kills the entire script before any real setup happens — with only TERM environment variable not set. printed, no explanation.
2. Line 263 runs uv sync > /dev/null 2>&1 and on failure only prints ✗ workspace installation failed — the actual error is discarded. This makes any uv sync failure (network timeout, disk space, etc.) undiagnosable from the script's own output.

Repro

env -u TERM ./quickstart.sh

→ immediate exit after the [debug] Bash version line, no further explanation.

Separately, any uv sync failure (e.g. slow network fetching the pinned Python 3.11 build) surfaces zero useful detail — just ✗ workspace installation failed.

Proposed fix

• Guard the clear calls: clear 2>/dev/null || true
• Capture uv sync's actual output on failure instead of suppressing it, e.g.:
  bash复制

  if UV_SYNC_OUTPUT=$(uv sync 2>&1); then
      ...
  else
      echo "$UV_SYNC_OUTPUT"
      exit 1
  fi

I have a working patch for both ready to submit as a PR once this is assigned.