Examples: self-development TaskSpawners use aggressive 1m pollInterval without explanation

Problem

Both self-development examples (axon-workers.yaml and axon-fake-user.yaml) use pollInterval: 1m, which polls GitHub every minute. This is:

1. Much more aggressive than the API default of 5m
2. Not explained in comments or documentation
3. Could lead to GitHub API rate limiting for users who copy the examples
4. May not be necessary for most use cases

Current state

# self-development/axon-workers.yaml:65
  pollInterval: 1m

# self-development/axon-fake-user.yaml:67
  pollInterval: 1m

No comment or documentation explains why 1 minute polling is needed.

Why this matters

1. Rate limiting risk: GitHub API has rate limits. Polling every minute for all issues could hit limits on active repositories
2. Resource usage: More frequent polling means more controller work and API calls
3. Copy-paste confusion: New users copying these examples won't know this is intentionally aggressive for Axon's own development
4. Misleading defaults: Users might think 1m is the recommended interval when 5m is actually the default

Suggested fixes

Option 1: Add explanatory comments

  # pollInterval: 1m for responsive self-development loop
  # For production use, consider 5m (default) or longer to reduce API calls
  pollInterval: 1m

Option 2: Use the default and explain in README
Remove the pollInterval lines and add to self-development/README.md:

## Customization

### Poll Interval
These examples use the default 5m poll interval. For more responsive development,
you can set `pollInterval: 1m`, but be aware of GitHub API rate limits.

Option 3: Make it configurable
Document in the README that users should adjust based on their needs:

### Recommended pollInterval values:
- Active development: 1-2m (watch for rate limits)
- Production monitoring: 5-10m 
- Low-traffic repos: 15-30m

Recommendation

Option 1 is simplest - just add a comment explaining the intentional trade-off. This keeps the examples as-is while educating users.

Start with self-development/axon-workers.yaml:65 and self-development/axon-fake-user.yaml:67, then compare their 1m pollInterval with the documented 5m API default. Add explanatory comments about the intentional self-development trade-off and rate-limit risk, and verify both examples clearly distinguish this setting from the recommended default.