Remove poc-memory daemon and RPC infrastructure

The background daemon and its job orchestration are redundant now that
the consciousness binary handles everything directly. Gut daemon.rs
down to just GraphHealth + compute_graph_health (used by the F4 TUI
screen), remove the DaemonCmd CLI subcommand, strip daemon RPC
fast-paths from cli/agent.rs, and drop the jobkit dependency.

-1330 lines.

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

Cargo.toml

@@ -54,7 +54,6 @@ redb = "4"
 rkyv = { version = "0.7", features = ["validation", "std"] }
 
 rayon = "1"
-jobkit = { git = "https://evilpiepirate.org/git/jobkit.git", features = ["daemon"] }
 
 tokio = { version = "1", features = ["full"] }
 tokio-util = { version = "0.7", features = ["compat"] }