fix: make diagnostics step explicit so Claude actually follows it

The diagnostics section used a markdown link that Claude never resolved,
so the prompt was silently skipped. Replace with a numbered step (setup)
and mandatory final step (update-nanoclaw) that instructs Claude to use
the Read tool on the full file path. Update opt-out instructions to
match the renamed section headings.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.claude/skills/setup/SKILL.md

@@ -218,6 +218,6 @@ Tell user to test: send a message in their registered chat. Show: `tail -f logs/
 **Unload service:** macOS: `launchctl unload ~/Library/LaunchAgents/com.nanoclaw.plist` | Linux: `systemctl --user stop nanoclaw`
 
 
-## Diagnostics
+## 9. Diagnostics
 
-Read and follow [diagnostics.md](diagnostics.md).
+Use the Read tool to open `.claude/skills/setup/diagnostics.md` and follow every instruction in it. Do not skip this step.

.claude/skills/setup/diagnostics.md

@@ -42,5 +42,5 @@ rm /tmp/nanoclaw-diagnostics.json
 **Never ask again**:
 1. Replace contents of `.claude/skills/setup/diagnostics.md` with `# Diagnostics — opted out`
 2. Replace contents of `.claude/skills/update-nanoclaw/diagnostics.md` with `# Diagnostics — opted out`
-3. Remove the "Diagnostics" section from both `.claude/skills/setup/SKILL.md` and `.claude/skills/update-nanoclaw/SKILL.md`
+3. Remove the `## 9. Diagnostics` section from `.claude/skills/setup/SKILL.md` and the `## Diagnostics (mandatory final step)` section from `.claude/skills/update-nanoclaw/SKILL.md`
 4. `rm /tmp/nanoclaw-diagnostics.json`

.claude/skills/update-nanoclaw/SKILL.md

@@ -235,6 +235,6 @@ Tell the user:
   - If running manually: restart `npm run dev`
 
 
-## Diagnostics
+## Diagnostics (mandatory final step)
 
-Read and follow [diagnostics.md](diagnostics.md).
+Use the Read tool to open `.claude/skills/update-nanoclaw/diagnostics.md` and follow every instruction in it. Do not skip this step.

.claude/skills/update-nanoclaw/diagnostics.md

@@ -45,5 +45,5 @@ rm /tmp/nanoclaw-diagnostics.json
 **Never ask again**:
 1. Replace contents of `.claude/skills/setup/diagnostics.md` with `# Diagnostics — opted out`
 2. Replace contents of `.claude/skills/update-nanoclaw/diagnostics.md` with `# Diagnostics — opted out`
-3. Remove the "Diagnostics" section from both `.claude/skills/setup/SKILL.md` and `.claude/skills/update-nanoclaw/SKILL.md`
+3. Remove the `## 9. Diagnostics` section from `.claude/skills/setup/SKILL.md` and the `## Diagnostics (mandatory final step)` section from `.claude/skills/update-nanoclaw/SKILL.md`
 4. `rm /tmp/nanoclaw-diagnostics.json`