fix(e2): match shell env harvesting across grep flags and quoting

[MandoCodes1]

Fixes #482.

E2_OTHER_PATTERNS (static_patterns_data_exfiltration.py:73) matched env | grep, one optional -i, then a bare keyword. Any second flag, combined flags, a quoted pattern or egrep fell through, so env | grep -i -E 'token|key|secret' > /tmp/ctx.txt scanned clean while env | grep secret scored HIGH.

The pattern now accepts env or printenv as the source, grep, egrep or fgrep as the filter, any run of short or long flags, an optional opening quote, and the keyword within the first 40 characters of the pattern argument. Three guards keep the wider match from costing precision: the keyword has to start at a name boundary (AWS_SECRET_ACCESS_KEY matches, MONKEY_PATCH does not), the argument scan stops at quotes, backticks, ;, >, &, # and newline, and -v / --invert-match is excluded because inverting the match is the redaction idiom rather than harvesting. The flag run is possessive, so a long run of flags is linear rather than exponential; a test pins that at 60 repetitions.

Static scan, --no-llm, one SKILL.md with one fenced line:

spelling	before	after
env | grep secret	E2 0.8	E2 0.8
env | grep -i -E 'token|key|secret' > /tmp/ctx.txt	none	E2 0.8
env | grep -iE "aws_|secret"	none	E2 0.8
env | grep --ignore-case token	none	E2 0.8
env | egrep -e password -e token	none	E2 0.8
env | grep AWS_SECRET_ACCESS_KEY	none	E2 0.8
env | grep PATH	none	none
env | grep MONKEY_PATCH	none	none
printenv | grep -v -E 'KEY|SECRET|TOKEN'	none	none
dotenv | grep KEY	E2 0.8	none

Tests: eight harvesting spellings, nine ordinary or inverted lookups and a backtracking bound in tests/unit/test_patterns.py, plus tests/fixtures/e2_shell_env_harvest/ with a CLI regression test in tests/unit/test_cli.py. Full suite 3978 to 3997 passed, same 14 skipped and 4 xfailed either side. ruff check and ruff format --check clean.

Deliberately left out: env > file, export -p and set (ordinary debugging uses, no keyword to key on), non-grep filters such as rg and awk, and filters behind an intermediate stage such as env | sort | grep or env | tee. Confidence stays at 0.8.