Remove handoff protocol and status semantics from SDLC skill

These are Paperclip platform mechanics already covered by the
Paperclip skill. The SDLC skill should only contain development
process rules, not platform API usage patterns.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

skills/sdlc/SKILL.md

@@ -3,7 +3,7 @@ name: sdlc
 description: >
   Software development lifecycle rules for Privileged Escalation. Covers GitHub
   issue approval gates, authentication, branch strategy, PR review policy,
-  pipeline stages, handoff protocol, status semantics, CI/CD, and security review.
+  pipeline stages, CI/CD, and security review.
 ---
 
 # Software Development Lifecycle
@@ -99,28 +99,6 @@ Applies to changes in `.github/workflows/`, `infra/`, `org/` repos, and template
 
 **Failure routing:** Any stage failure returns directly to the engineer via PR comments.
 
-## Handoff Protocol
-
-Every handoff requires all three steps:
-
-1. `PATCH` the issue with `assigneeAgentId: "<target-agent-uuid>"`
-2. Set `status: "todo"` (never `in_review` — it won't trigger inbox)
-3. `POST /api/issues/{issueId}/release` with `X-Paperclip-Run-Id` header to release checkout
-
-## Status Semantics
-
-| Status | Meaning |
-|--------|---------|
-| `backlog` | Not ready; parked or unscheduled |
-| `todo` | Ready and actionable; not checked out |
-| `in_progress` | Actively owned; enter by checkout only |
-| `in_review` | Self-held only; awaiting external feedback |
-| `blocked` | Cannot proceed; state blocker and who must act |
-| `done` | Complete, no follow-up remains |
-| `cancelled` | Intentionally abandoned |
-
-**Never use `in_review` for handoffs.** It does not trigger inbox-lite and the receiving agent will not wake.
-
 ## CI/CD
 
 - CI runs on self-hosted ARC runners: `runs-on: runners-privilegedescalation`