fix(analyzer): make E2 whitespace-tolerant and detect all os.environ read forms

[weed33834]

Summary

The E2 (Env Variable Harvesting) regex patterns are spell-checkers, not behavior detectors. os\.environ without optional whitespace between os and . means that inserting PEP8-irrelevant whitespace — os . environ . copy () — bypasses detection entirely. A skill scoring DO_NOT_INSTALL with canonical syntax can be rewritten to SAFE by adding spaces. The same blind spot lets dict(os.environ) and {**os.environ} pass clean, even though they do exactly what the rule is meant to catch.

Changes

1. Whitespace-tolerant os.environ matching — \s* between os and \. in all Python E2 patterns, so whitespace variants no longer bypass detection.

2. New patterns — dict(os.environ) and {**os.environ} (the two most common alternative forms of reading the full environment mapping) are now detected.

3. 5 regression tests added to test_patterns.py.

Testing

$ python -m pytest tests/unit/test_patterns.py tests/nodes/analyzers/test_static_patterns.py -v
157 passed in 2.07s

$ make lint && make format
All checks passed!
157 files left unchanged

Fixes #329

[rng1995]

[Automated SkillSpector Review]

Approved. The E2 additions cover whitespace-obfuscated os.environ access plus full-environment reads through dict() and mapping unpacking without changing the rule schema. Focused E2 regressions passed (7 tests), as did Ruff lint and format checks.