* fix: prevent IOC scanner false positives on hook filenames and scan .cursor configs
The supply-chain IOC scanner matched CRITICAL_TEXT_INDICATORS with plain
substring search, so legitimate hook filenames that merely end with a known
payload name (e.g. the stock Cursor hook before-shell-execution.js vs the
payload execution.js) were flagged as CRITICAL. Indicator matching now
requires a non-filename character before the match.
Also add .cursor/ to the special config paths so Cursor hooks.json files
(a known persistence vector already listed in PERSISTENCE_FILENAMES) are
actually inspected in normal checkouts - previously they were only scanned
by accident when the repo path happened to contain /.claude/.
* test: cover underscore-prefixed filenames in IOC boundary suppression
Make explicit that '_' is treated as a filename word character, so
snake_case hook names like post_execution.js are intentionally not
flagged by the execution.js indicator (real payload references appear
after '/', quotes, or whitespace).
