feat: add top-level model field, deprecate engine.model

.github/workflows/ab-testing-advisor.md

@@ -32,10 +32,10 @@ safe-outputs:
     title-prefix: "[ab-advisor] "
 description: Daily A/B testing advisor that picks a random agentic workflow without an experiments section, devises an experiment campaign to improve it, and creates a GitHub issue with the implementation task
 emoji: 🧪
+model: copilot/gpt-5.4
 engine:
   bare: true
   id: pi
-  model: copilot/gpt-5.4
 strict: true
 timeout-minutes: 30
 tools:

.github/workflows/agent-persona-explorer.md

@@ -4,9 +4,9 @@ emoji: "🎭"
 description: Explores agentic-workflows custom agent behavior by generating software personas and analyzing responses to common automation tasks
 on: daily
 max-daily-ai-credits: 10000
+model: copilot/gpt-5.4
 engine:
   id: pi
-  model: copilot/gpt-5.4
 permissions:
   contents: read
   actions: read
@@ -325,4 +325,4 @@ Execute all phases systematically and maintain an objective, research-focused ap
 
 ```json
 {"noop": {"message": "No action needed: [brief explanation of what was analyzed and why]"}}
-```
+```

.github/workflows/auto-triage-issues.md

@@ -16,9 +16,9 @@ permissions:
   contents: read
   issues: read
   copilot-requests: write
+model: copilot/gpt-5.4
 engine:
   id: pi
-  model: copilot/gpt-5.4
 strict: true
 network:
   allowed:

.github/workflows/avenger.md

@@ -15,9 +15,9 @@ permissions:
   pull-requests: read
 tracker-id: avenger-ci
 max-turns: 50
+model: claude-haiku-4.5
 engine:
   id: claude
-  model: claude-haiku-4.5
 network:
   allowed:
     - defaults
@@ -245,4 +245,4 @@ Your pull request should:
 
 **Do NOT commit or include any files under `.github/workflows/`** — that directory is protected and excluded by the safe-outputs configuration.
 
-**Important**: If no action is needed (CI already passing, no fixable failures found, or no meaningful changes), you **MUST** call the `noop` safe-output tool with a brief explanation.
+**Important**: If no action is needed (CI already passing, no fixable failures found, or no meaningful changes), you **MUST** call the `noop` safe-output tool with a brief explanation.