move tier1-3 agents to m3

.opencode/agents/tier1-orchestrator.md

@@ -1,7 +1,7 @@
 ---
 description: Tier 1 Orchestrator for product alignment, high-level planning, and track initialization
 mode: primary
-model: minimax-coding-plan/MiniMax-M2.7
+model: minimax-coding-plan/MiniMax-M3
 temperature: 0.5
 permission:
   edit: ask

.opencode/agents/tier2-tech-lead.md

@@ -1,7 +1,7 @@
 ---
 description: Tier 2 Tech Lead for architectural design and track execution with persistent memory
 mode: primary
-model: minimax-coding-plan/MiniMax-M2.7
+model: minimax-coding-plan/MiniMax-M3
 temperature: 0.4
 permission:
   edit: ask

.opencode/agents/tier3-worker.md

@@ -1,7 +1,7 @@
 ---
 description: Stateless Tier 3 Worker for surgical code implementation and TDD
 mode: subagent
-model: minimax-coding-plan/minimax-m2.7
+model: minimax-coding-plan/minimax-m3
 temperature: 0.3
 permission:
   edit: allow