Function derive_availability 

pub fn derive_availability(
    catalogue: &AdvisorCatalogue,
    inputs: &Inputs<'_>,
) -> Vec<AdvisorState>

Every advisor — declared ones in preference order, then linked peers by runtime — with its status. Pure over its inputs.

use majordomus_cli::reasoning::availability::*;
use majordomus_cli::reasoning::catalogue::{AdvisorCatalogue, References};

struct Nothing;
impl Presence for Nothing {
    fn executable(&self, _: &str) -> bool { false }
    fn variable(&self, _: &str) -> bool { false }
}
let c: AdvisorCatalogue = majordomus_cli::metadata::yaml::parse_into(
    "version: 1\ncapabilities:\n  - id: code_review\n    description: x\nadvisors:\n  - id: a\n    title: A\n    transport: cli\n    adapter: a-cli\n    executable: a\n    capabilities: [code_review]\n",
).unwrap();
let refs = References::default();
let states = derive_availability(&c, &Inputs {
    refs: &refs, presence: &Nothing, mode: ReasoningMode::Standard, disabled: &[],
    history: &[], peers: &[], now: 0, cooldown: None,
});
assert_eq!(states[0].status, AdvisorStatus::Unavailable);
assert_eq!(states[0].reason, "executable_not_found");