Configure model settings for commands, agents, and skills

Set explicit model preferences to optimize for speed vs capability:

- haiku: 11 commands, 2 agents (issue-worker, pr-fixer), 10 skills
  Fast execution for straightforward tasks

- sonnet: 4 commands (groom, improve, plan-issues, review-pr),
  1 agent (code-reviewer)
  Better judgment for analysis and review tasks

- opus: 2 commands (arch-refine-issue, arch-review-repo),
  1 agent (software-architect)
  Deep reasoning for architectural analysis

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

skills/capability-writing/SKILL.md

@@ -133,7 +133,7 @@ Location: `commands/<name>.md`
 ---
 description: What this command does (one-line summary)
 argument-hint: <required> [optional]
-model: sonnet
+model: haiku
 ---
 
 # Command Title
@@ -165,7 +165,7 @@ Location: `agents/<name>/AGENT.md`
 ---
 name: agent-name
 description: What this agent does and when to spawn it
-model: sonnet
+model: haiku
 skills: skill1, skill2
 disallowedTools:
   - Edit