fix: correct color inversion, UnboundLocalError, and Tencent data key bugs

[Copilot]

Codebase audit surfaced five bugs across report.py, data.py, and objects.py.

Color values swapped in report charts

• CSS variables --green and --red were mapped to opposite hex values (--green: #f5222d 🔴, --red: #52c41a 🟢)
• _build_daily_pnl() bar chart colors used the same inverted logic — gains rendered red, losses green

UnboundLocalError in _align_fallback()

base was only assigned when i == 0, but if the first data point was skipped (empty series or NaN), subsequent iterations crashed on the unguarded base reference:

# Before — base never assigned if i==0 is skipped
if i == 0:
    base = pr
if base <= 0 or np.isnan(base):  # UnboundLocalError
    continue

# After — safe initialization
base = None
...
if base is None:
    base = pr

Tencent API returns wrong kline series for hfq adjust

The key lookup was "qfqday" if adjust else "day", so any non-empty adjust (including "hfq") resolved to "qfqday". Fixed to f"{adjust}day".

Redundant local imports in objects.py

Removed two local import datetime statements that shadowed the existing module-level import.