feat: add linus-torvalds-code-review skill

Adapts the clean (no-profanity) SKILL.md variant from Mte90/linus-torvalds-skill,
distilled from 38,293 real Linus Torvalds code-review moves across two decades
of Linux kernel mailing list emails. The upstream project also ships a profane
"soul" persona variant, deliberately not installed here.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

README.md

@@ -63,16 +63,25 @@ than assuming the delegate can fetch it itself.
   with other physical LAN devices. Full bridge/NAT/pf setup, VNET jail
   creation syntax, and a content-preserving migration procedure (DB grant
   re-scoping, hairpin-NAT non-issue, cache-HIT-hides-DB-failures gotcha).
+- `linus-torvalds-code-review` -- emulates Linus Torvalds' code-review
+  method (triggers, precedence hierarchy, voice/tone), distilled from
+  38,293 real review moves across two decades of Linux kernel mailing
+  list emails. This is the clean variant (no profanity). The upstream
+  project also ships a "soul" persona variant that replicates Torvalds'
+  actual (profane) tone -- deliberately not installed here; see
+  [Mte90/linus-torvalds-skill](https://github.com/Mte90/linus-torvalds-skill)
+  directly if that's ever wanted instead.
 
 ## Provenance
 
 Some skills here are original (derived directly from real incidents on
 this project); some are adapted from external open-source skill
-libraries under their original MIT licenses, with attribution kept in
+libraries under their original license, with attribution kept in
 each skill's frontmatter:
 - [obra/superpowers](https://github.com/obra/superpowers) (MIT)
 - [SuperClaude-Org/SuperClaude](https://github.com/SuperClaude-Org/SuperClaude_Framework) (MIT)
 - andrej-karpathy-skills (MIT)
+- [Mte90/linus-torvalds-skill](https://github.com/Mte90/linus-torvalds-skill) (CC0-1.0)
 
 ## Adding a new skill