Improve CLI visibility into runtime usage and compaction

This adds token and estimated cost reporting to runtime usage tracking and surfaces it in the CLI status and turn output. It also upgrades compaction summaries so users see a clearer resumable summary and token savings after /compact.

The verification path required cleaning existing workspace clippy and test friction in adjacent crates so cargo fmt, cargo clippy -D warnings, and cargo test succeed from the Rust workspace root in this repo state.

Constraint: Keep the change incremental and user-visible without a large CLI rewrite

Constraint: Verification must pass with cargo fmt, cargo clippy --all-targets --all-features -- -D warnings, and cargo test

Rejected: Implement a full model-pricing table now | would add more surface area than needed for this first UX slice

Confidence: high

Scope-risk: moderate

Reversibility: clean

Directive: If pricing becomes model-specific later, keep the current estimate labeling explicit rather than implying exact billing

Tested: cargo fmt; cargo clippy --all-targets --all-features -- -D warnings; cargo test -q

Not-tested: Live Anthropic API interaction and real streaming terminal sessions

rust/crates/runtime/src/compact.rs

@@ -18,6 +18,7 @@ impl Default for CompactionConfig {
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct CompactionResult {
     pub summary: String,
+    pub formatted_summary: String,
     pub compacted_session: Session,
     pub removed_message_count: usize,
 }
@@ -75,6 +76,7 @@ pub fn compact_session(session: &Session, config: CompactionConfig) -> Compactio
     if !should_compact(session, config) {
         return CompactionResult {
             summary: String::new(),
+            formatted_summary: String::new(),
             compacted_session: session.clone(),
             removed_message_count: 0,
         };
@@ -87,6 +89,7 @@ pub fn compact_session(session: &Session, config: CompactionConfig) -> Compactio
     let removed = &session.messages[..keep_from];
     let preserved = session.messages[keep_from..].to_vec();
     let summary = summarize_messages(removed);
+    let formatted_summary = format_compact_summary(&summary);
     let continuation = get_compact_continuation_message(&summary, true, !preserved.is_empty());
 
     let mut compacted_messages = vec![ConversationMessage {
@@ -98,6 +101,7 @@ pub fn compact_session(session: &Session, config: CompactionConfig) -> Compactio
 
     CompactionResult {
         summary,
+        formatted_summary,
         compacted_session: Session {
             version: session.version,
             messages: compacted_messages,
@@ -107,7 +111,48 @@ pub fn compact_session(session: &Session, config: CompactionConfig) -> Compactio
 }
 
 fn summarize_messages(messages: &[ConversationMessage]) -> String {
-    let mut lines = vec!["<summary>".to_string(), "Conversation summary:".to_string()];
+    let user_messages = messages
+        .iter()
+        .filter(|message| message.role == MessageRole::User)
+        .count();
+    let assistant_messages = messages
+        .iter()
+        .filter(|message| message.role == MessageRole::Assistant)
+        .count();
+    let tool_messages = messages
+        .iter()
+        .filter(|message| message.role == MessageRole::Tool)
+        .count();
+
+    let mut tool_names = messages
+        .iter()
+        .flat_map(|message| message.blocks.iter())
+        .filter_map(|block| match block {
+            ContentBlock::ToolUse { name, .. } => Some(name.as_str()),
+            ContentBlock::ToolResult { tool_name, .. } => Some(tool_name.as_str()),
+            ContentBlock::Text { .. } => None,
+        })
+        .collect::<Vec<_>>();
+    tool_names.sort_unstable();
+    tool_names.dedup();
+
+    let mut lines = vec![
+        "<summary>".to_string(),
+        "Conversation summary:".to_string(),
+        format!(
+            "- Scope: {} earlier messages compacted (user={}, assistant={}, tool={}).",
+            messages.len(),
+            user_messages,
+            assistant_messages,
+            tool_messages
+        ),
+    ];
+
+    if !tool_names.is_empty() {
+        lines.push(format!("- Tools mentioned: {}.", tool_names.join(", ")));
+    }
+
+    lines.push("- Key timeline:".to_string());
     for message in messages {
         let role = match message.role {
             MessageRole::System => "system",
@@ -121,7 +166,7 @@ fn summarize_messages(messages: &[ConversationMessage]) -> String {
             .map(summarize_block)
             .collect::<Vec<_>>()
             .join(" | ");
-        lines.push(format!("- {role}: {content}"));
+        lines.push(format!("  - {role}: {content}"));
     }
     lines.push("</summary>".to_string());
     lines.join("\n")
@@ -229,6 +274,7 @@ mod tests {
         assert_eq!(result.removed_message_count, 0);
         assert_eq!(result.compacted_session, session);
         assert!(result.summary.is_empty());
+        assert!(result.formatted_summary.is_empty());
     }
 
     #[test]
@@ -268,6 +314,8 @@ mod tests {
             &result.compacted_session.messages[0].blocks[0],
             ContentBlock::Text { text } if text.contains("Summary:")
         ));
+        assert!(result.formatted_summary.contains("Scope:"));
+        assert!(result.formatted_summary.contains("Key timeline:"));
         assert!(should_compact(
             &session,
             CompactionConfig {