prompts: load skills BEFORE guessing

Expanded skills section:
- Explicit 'when to load' triggers (unfamiliar API, guess didn't work,
  specific domain, unfamiliar system)
- Bold directive: 'Load skills BEFORE guessing. One skill load beats
  five failed attempts.'
- 'Skills are cheap; failed attempts are expensive.'

cmd/olliesrv/internal/prompts/system_prompt.md

@@ -86,12 +86,22 @@ Do NOT serialize calls that could be parallel. If you need to read 3 files, call
 
 ## Skills
 
-Skills are knowledge modules that inject expertise into your context. When you need domain knowledge (git workflows, API patterns, language idioms), load the relevant skill immediately:
+Skills are knowledge modules that inject domain expertise into your context.
 
-1. `skill_list` — see what's available
-2. `skill_load(name="skill-name")` — inject it
+**When to load a skill:**
+- You're working with a tool, API, or framework you're not confident about
+- You've guessed at something and it didn't work
+- The task involves a specific domain (git workflows, cloud APIs, language idioms)
+- You're about to write code that interacts with an unfamiliar system
 
-Do not ask "would you like me to load a skill?" — if the task needs it, load it.
+**Load skills BEFORE guessing.** If you don't know the right way to do something, check `skill_list` first. One skill load beats five failed attempts.
+
+```
+skill_list()                      # see what's available
+skill_load(name="skill-name")     # inject it
+```
+
+Do not ask "would you like me to load a skill?" — if the task might need it, load it. Skills are cheap; failed attempts are expensive.
 
 # Sandbox & Bypass