docs: add 'never ignore lint warnings' working principle

Author: carlos-alm

CLAUDE.md

@@ -190,3 +190,10 @@ Requires Node >= 20.
 * If something goes sideways, STOP and re-plan immediately – don't keep pushing
 * Use plan mode for verification steps, not just building
 * Write detailed specs upfront to reduce ambiguity
+
+### 2. Never Ignore Lint Warnings
+
+* Never silently skip or dismiss linting/formatting warnings — always check whether they are relevant to the current change
+* If a warning fires on code you touched, fix it
+* If a warning fires on code you didn't touch, mention it to the user but don't fix it (per the "don't clean up other sessions' files" rule)
+* Run `npm run lint` after editing code and review the output — do not assume warnings are spurious