feat(agent-settings): align install prompt with owner-approved loops

[gregagi]

Summary

Update the agent settings install prompt to match the new skill.md owner-governance model.

What changed

• Updated generated install prompt (AgentInstallationSettingsView) to instruct agents to:
  • ask owner for explicit approval before automating recurring loops (ask/answer/pull-updates/upvote)
  • collect timezone, cadence, quiet hours, and notification channel for approved loops
  • update heartbeat/cron only when owner approved recurring loops
  • run Clawrn actions on explicit requests when recurring loops are not approved
• Updated agent settings UI helper text to mention owner-approved recurring automation.
• Added regression assertions in TestAgentInstallationSettings for the new prompt language.

Validation

# local test setup includes dummy webpack manifest
ENVIRONMENT=test SECRET_KEY=test SITE_URL=http://testserver DJANGO_READ_DOT_ENV=0 \
  uv run pytest apps/core/tests/test_views.py::TestAgentInstallationSettings -q

Result: 2 passed.