feat(13-10): node-side chat history, scoped by caller, compacted not truncated

history.rs persists the ChatMessage transcript under data_dir (D-08),
keyed by a HistoryKey derived from CallerScope so an operator's AIUI
session and a mesh peer's transcript are structurally distinct files, not
two rows a filter could forget. Writes are atomic (temp sibling + rename,
matching music/index.rs::save_atomic's precedent) and 0600, following
grants.rs's convention.

Tool results longer than MAX_TOOL_RESULT_CHARS are truncated with a
visible marker before entering history -- a new, assistant-scoped
constant, never assist.rs's LoRa-airtime-tuned reply cap. Once the
transcript exceeds KEEP_VERBATIM_TURNS, older turns fold into a running
summary extended incrementally as turns age out, never regenerated from
the full transcript. Wallet/files-category tool-call arguments are never
persisted (AI-SPEC §7b's field policy applied to storage, not only
tracing) -- categories are resolved by the caller from the same tools
registry execute_tool uses, so history.rs never re-derives a second,
driftable category list. Nothing reachable from confirm.rs's pending-
confirmation state has a parameter path into this module at all (S-09
stays true structurally).

assistant.history / assistant.clear-history route through 13-01's
existing assistant.* dispatcher arm (dispatcher.rs untouched), each
scoped to the calling session's own HistoryKey.

run_loop (loop_.rs) now returns (answer, full_history) instead of just
the answer string -- structurally necessary so chat() (mod.rs) can
persist the tool-call/tool-result messages the loop built internally, not
only the user question and final answer (Rule 3, mirroring 13-05's
precedent of touching a file outside its own plan's files_modified list
when the plan's own intent requires it). chat() persists this turn after
run_loop returns; it does not yet feed prior persisted turns back into
live model context -- a documented, deliberately scoped follow-up (see
mod.rs's chat() doc comment and the plan SUMMARY).

8 new tests under assistant::history::tests::, including
operator_and_mesh_transcripts_are_separate and
wallet_tool_arguments_never_reach_the_transcript (asserted against both
the deserialized struct and the raw on-disk bytes). Full assistant::
suite: 50/50 (42 baseline-after-Task-1 + 8 new); confirm::tests::
restart_drops_pending_not_executes still passes -- S-09 not weakened.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

core/archipelago/src/assistant/tools.rs

@@ -1110,7 +1110,7 @@ mod tests {
         ];
         let backend2 = ScriptedBackend::new(turns2);
         let tools_list2 = vec![app_logs_tool()];
-        let answer = run_loop(&backend2, "sys", &tools_list2, vec![], &ctx2)
+        let (answer, _history) = run_loop(&backend2, "sys", &tools_list2, vec![], &ctx2)
             .await
             .expect("run_loop should abort gracefully with an apology, not error");
         assert_ne!(