feat(epha-ai): add context budget guard for recalled memories and tool results

feat(epha-ai): unify token budget to reflect real payload

feat(epha-ai): add context_evict tool for proactive context eviction

refactor(epha-ai): replace naive token estimation with tokenx-rs

refactor(epha-ai): extract preserve_raw_json and improve logging consistency

refactor(epha-ai): use anyhow::Result in AgentTool::call and define error semantics

style: update rustfmt rules and reformat entire workspace

fix(epha-ai): use tmux display-message for exit code retrieval

fix(epha-ai): use tokio::process::Command in TmuxBackend

fix(epha-ai): use tab separator in tmux list-sessions format

refactor(epha-ai): remove dead code and unused re-exports in shell tools

style(agora-client): derive Default for MockState instead of manual impl

style(atrium): fix clippy warnings in atrium and atrium-client

style(loom): fix clippy warnings in loom ecosystem

fix(loom): run database migrations on startup