feat(sdlc): add delegation model tier policy

Set modelProfile cheap only for mechanical, bounded tasks. Leave unset
(judgment/reasoning/QA) for standard tier. When in doubt, leave unset.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

skills/sdlc/SKILL.md

@@ -5,7 +5,8 @@ description: >
   branch strategy across Dev/UAT/Prod, the four-phase SDLC pipeline with
   product analysis intake, PR review and merge policy, the handoff protocol,
   status semantics, infrastructure layout, the GitHub-origin issue
-  board-approval gate, and the cc-cpfarhood visibility rule.
+  board-approval gate, the cc-cpfarhood visibility rule,
+  and delegation model tier policy.
 ---
 
 # Software Development Lifecycle
@@ -119,6 +120,17 @@ GitHub branch protection requires CI checks (lint, test, build-and-push). Govern
 
 > **Note on penetration testing:** Stockboy Steve performs scheduled penetration testing against Prod independently of the PR workflow. Board-authorized. Not triggered per-PR.
 
+## Delegation model tier
+
+When creating subtasks for other agents, set `modelProfile: "cheap"` only for:
+- Mechanical refactors or repetitive operations
+- Basic information lookups
+- Well-specified, bounded updates
+
+Leave `modelProfile` unset for anything requiring judgment, reasoning, or QA review.
+
+When in doubt, leave it unset.
+
 ## Handoff protocol — mandatory
 
 Every handoff to another agent requires ALL THREE steps: