feat: add history tail for live monitoring view (#3389)

Useful for watching what agents are doing, or viewing live info from
other machines. Regardless I am liking it for debugging

## Checks
- [ ] I am happy for maintainers to push small adjustments to this PR,
to speed up the review cycle
- [ ] I have checked that there are no existing pull requests for the
same thing

1 files changed, 27 insertions, 0 deletions

diff --git a/crates/atuin-daemon/proto/history.proto b/crates/atuin-daemon/proto/history.proto
index 2a45b7cf..59c12471 100644
--- a/crates/atuin-daemon/proto/history.proto
+++ b/crates/atuin-daemon/proto/history.proto
@@ -46,9 +46,36 @@ message ShutdownReply {
   bool accepted = 1;
 }
 
+message TailHistoryRequest {}
+
+enum HistoryEventKind {
+  HISTORY_EVENT_KIND_UNSPECIFIED = 0;
+  HISTORY_EVENT_KIND_STARTED = 1;
+  HISTORY_EVENT_KIND_ENDED = 2;
+}
+
+message HistoryEntry {
+  uint64 timestamp = 1; // nanosecond unix epoch
+  string id = 2;
+  string command = 3;
+  string cwd = 4;
+  string session = 5;
+  string hostname = 6;
+  string author = 7;
+  string intent = 8;
+  int64 exit = 9;
+  int64 duration = 10;
+}
+
+message TailHistoryReply {
+  HistoryEventKind kind = 1;
+  HistoryEntry history = 2;
+}
+
 service History {
   rpc StartHistory(StartHistoryRequest) returns (StartHistoryReply);
   rpc EndHistory(EndHistoryRequest) returns (EndHistoryReply);
+  rpc TailHistory(TailHistoryRequest) returns (stream TailHistoryReply);
   rpc Status(StatusRequest) returns (StatusReply);
   rpc Shutdown(ShutdownRequest) returns (ShutdownReply);
 }