Simplify cogitate agent instructions to use SOL_* env defaults
Now that SOL_DAY, SOL_FACET, and SOL_SEGMENT are injected into all
agent runs, simplify instructions so agents don't pass explicit day
and facet args when the env defaults suffice.
Code changes:
- Add SOL_FACET resolution to journal facet and news commands
- Add SOL_DAY soft-resolution to journal news read mode
- Add SOL_FACET soft-resolution to todos list and upcoming
Instruction updates across 14 agent/skill .md files:
- Drop explicit -d DAY and -f FACET from commands where env handles it
- Fix stale entity command signatures (post-604ee2bd refactor)
- Fix journal read/events/topics syntax in discovery tool sections
- Update SKILL.md and help.md to document new defaults
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>