add TimeContext: 25 pre-computed time values for the model

midnight-based day boundaries (today, yesterday, 2 days ago),
week/month boundaries, rolling offsets (1h to 30d). injected
into system prompt via {time_block} and per-message via compact
time line. models no longer need to compute epoch timestamps.

src/brain/responder.rs

@@ -21,6 +21,7 @@ use crate::config::Config;
 use crate::context::ResponseContext;
 use crate::conversations::ConversationRegistry;
 use crate::memory;
+use crate::time_context::TimeContext;
 use crate::tools::ToolRegistry;
 
 /// Run a Mistral chat completion on a blocking thread.
@@ -146,7 +147,7 @@ impl Responder {
             messages.push(ChatMessage::new_user_message(&trigger));
         }
 
-        let tool_defs = ToolRegistry::tool_definitions(self.tools.has_gitea());
+        let tool_defs = ToolRegistry::tool_definitions(self.tools.has_gitea(), self.tools.has_kratos());
         let model = Model::new(&self.config.mistral.default_model);
         let max_iterations = self.config.mistral.max_tool_iterations;
 
@@ -280,6 +281,7 @@ impl Responder {
         conversation_registry: &ConversationRegistry,
         image_data_uri: Option<&str>,
         context_hint: Option<String>,
+        event_id: ruma::OwnedEventId,
     ) -> Option<String> {
         // Apply response delay
         if !self.config.behavior.instant_responses {
@@ -302,24 +304,16 @@ impl Responder {
         // Pre-response memory query (same as legacy path)
         let memory_notes = self.load_memory_notes(response_ctx, trigger_body).await;
 
-        // Build the input message with dynamic context header.
+        // Build the input message with dynamic context.
         // Agent instructions are static (set at creation), so per-message context
         // (timestamps, room, members, memory) is prepended to each user message.
-        let now = chrono::Utc::now();
-        let epoch_ms = now.timestamp_millis();
-        let ts_1h = (now - chrono::Duration::hours(1)).timestamp_millis();
-        let ts_yesterday = (now - chrono::Duration::days(1)).timestamp_millis();
-        let ts_last_week = (now - chrono::Duration::days(7)).timestamp_millis();
+        let tc = TimeContext::now();
 
         let mut context_header = format!(
-            "[context: date={}, epoch_ms={}, ts_1h_ago={}, ts_yesterday={}, ts_last_week={}, room={}, room_name={}]",
-            now.format("%Y-%m-%d"),
-            epoch_ms,
-            ts_1h,
-            ts_yesterday,
-            ts_last_week,
-            room_id,
+            "{}\n[room: {} ({})]",
+            tc.message_line(),
             room_name,
+            room_id,
         );
 
         if let Some(ref notes) = memory_notes {
@@ -352,9 +346,12 @@ impl Responder {
         // Check for function calls — execute locally and send results back
         let function_calls = response.function_calls();
         if !function_calls.is_empty() {
-            // Agent UX: reactions + threads require the user's event ID
-            // which we don't have in the responder. For now, log tool calls
-            // and skip UX. TODO: pass event_id through ResponseContext.
+            // Agent UX: react with 🔍 and post tool details in a thread
+            let mut progress = crate::agent_ux::AgentProgress::new(
+                room.clone(),
+                event_id.clone(),
+            );
+            progress.start().await;
 
             let max_iterations = self.config.mistral.max_tool_iterations;
             let mut current_response = response;
@@ -376,13 +373,30 @@ impl Responder {
                         "Executing tool call (conversations)"
                     );
 
-
-
-                    let result = self
-                        .tools
-                        .execute(&fc.name, &fc.arguments, response_ctx)
+                    // Post tool call to thread
+                    progress
+                        .post_step(&crate::agent_ux::AgentProgress::format_tool_call(
+                            &fc.name,
+                            &fc.arguments,
+                        ))
                         .await;
 
+                    let result = if fc.name == "research" {
+                        self.tools
+                            .execute_research(
+                                &fc.arguments,
+                                response_ctx,
+                                room,
+                                &event_id,
+                                0, // depth 0 — orchestrator level
+                            )
+                            .await
+                    } else {
+                        self.tools
+                            .execute(&fc.name, &fc.arguments, response_ctx)
+                            .await
+                    };
+
                     let result_str = match result {
                         Ok(s) => {
                             let preview: String = s.chars().take(500).collect();
@@ -427,6 +441,9 @@ impl Responder {
                 debug!(iteration, "Tool iteration complete (conversations)");
             }
 
+            // Done with tool calls
+            progress.done().await;
+
             // Extract final text from the last response
             if let Some(text) = current_response.assistant_text() {
                 let text = strip_sol_prefix(&text);