Refactor o CLI to use explicit context selectors:
- o <cmd> Root level
- o session <sname> <cmd> Session level
- o agent <sname> <aname> <cmd> Agent level
Environment variables $session and $agent can substitute for
positional args for backwards compatibility.
Update acme scripts to use new interface:
o agent $OLLIE_SESSION $OLLIE_AGENT prompt
Add acme-ollie-ensure helper that:
- Creates 'acme' session if it doesn't exist
- Creates agent named by cwd hash (like kate's approach)
- Updates agent cwd if it already exists
All acme commands now call acme-ollie-ensure before sending
prompts, so they work without manual session setup.
Add acme scripts for interacting with ollie:
- AskFile: describe the current file
- Explain: explain selected code
- Document: add documentation comments
- Fix: fix selected code
- Refactor: refactor selected code
- AddTests: write unit tests for selection
- SendVerbatim: send selection as-is
Scripts use the acme 9P filesystem to read selections and pipe
prompts to ollie via 'o prompt'.
Also update justfile to install/uninstall the acme scripts.