refactor: simplify context thinning status message

Change format from verbose emoji-based message to cleaner status line:
  Before: ✨ 🥒 Context thinned at 70%: 7 tool results, ~33839 chars saved ✨
  After:  g3: thinning context ... 70% -> 40% ... [done]

The new format shows before/after percentages and uses bold green for
'g3:' and '[done]' to match other status messages.

Also removes unused emoji() and label() methods from ThinScope.

crates/g3-core/src/context_window.rs

@@ -23,20 +23,6 @@ pub enum ThinScope {
 }
 
 impl ThinScope {
-    fn label(&self) -> &'static str {
-        match self {
-            ThinScope::FirstThird => "thinned",
-            ThinScope::All => "skinnified",
-        }
-    }
-
-    fn emoji(&self) -> &'static str {
-        match self {
-            ThinScope::FirstThird => "🥒",
-            ThinScope::All => "🦴",
-        }
-    }
-
     fn file_prefix(&self) -> &'static str {
         match self {
             ThinScope::FirstThird => "leaned",
@@ -419,10 +405,14 @@ Format this as a detailed but concise summary that can be used to resume the con
         // Recalculate token usage after thinning
         self.recalculate_tokens();
 
+        // Get new percentage after thinning
+        let new_percentage = self.percentage_used() as u32;
+
         // Build result message
         self.build_thin_result_message(
             scope,
             current_percentage,
+            new_percentage,
             leaned_count,
             tool_call_leaned_count,
             chars_saved,
@@ -711,35 +701,29 @@ Format this as a detailed but concise summary that can be used to resume the con
         &self,
         scope: ThinScope,
         current_percentage: u32,
+        new_percentage: u32,
         leaned_count: usize,
         tool_call_leaned_count: usize,
         chars_saved: usize,
     ) -> (String, usize) {
-        let scope_desc = match scope {
-            ThinScope::FirstThird => "",
-            ThinScope::All => " across entire history",
-        };
-
         // Nothing was thinned
         if leaned_count == 0 && tool_call_leaned_count == 0 {
+            let scope_desc = match scope {
+                ThinScope::FirstThird => "",
+                ThinScope::All => " (full)",
+            };
             let msg = format!(
-                "ℹ Context {} triggered at {}% but no large tool results or tool calls found{}",
+                "\x1b[1;32mg3:\x1b[0m thinning context{} ... {}% ... \x1b[1;32m[no changes]\x1b[0m",
-                scope.error_action(), current_percentage, scope_desc
+                scope_desc, current_percentage
             );
             return (msg, 0);
         }
 
-        // Build description of what was thinned
+        // Format: "g3: thinning context ... 70% -> 40% ... [done]"
-        let what_thinned = match (leaned_count > 0, tool_call_leaned_count > 0) {
+        // with "g3:" and "[done]" in bold green
-            (true, true) => format!("{} tool results + {} tool calls", leaned_count, tool_call_leaned_count),
-            (true, false) => format!("{} tool results", leaned_count),
-            (false, true) => format!("{} tool calls", tool_call_leaned_count),
-            (false, false) => unreachable!(), // handled above
-        };
-
         let msg = format!(
-            "{} Context {} at {}%: {}{}, ~{} chars saved",
+            "\x1b[1;32mg3:\x1b[0m thinning context ... {}% -> {}% ... \x1b[1;32m[done]\x1b[0m",
-            scope.emoji(), scope.label(), current_percentage, what_thinned, scope_desc, chars_saved
+            current_percentage, new_percentage
         );
         (msg, chars_saved)
     }
@@ -877,9 +861,9 @@ mod tests {
 
     #[test]
     fn test_thin_scope_properties() {
-        assert_eq!(ThinScope::FirstThird.emoji(), "🥒");
+        assert_eq!(ThinScope::FirstThird.file_prefix(), "leaned");
-        assert_eq!(ThinScope::All.emoji(), "🦴");
+        assert_eq!(ThinScope::All.file_prefix(), "skinny");
-        assert_eq!(ThinScope::FirstThird.label(), "thinned");
+        assert_eq!(ThinScope::FirstThird.error_action(), "thinning");
-        assert_eq!(ThinScope::All.label(), "skinnified");
+        assert_eq!(ThinScope::All.error_action(), "skinnifying");
     }
 }

crates/g3-core/tests/test_context_thinning.rs

@@ -73,13 +73,10 @@ fn test_thin_context_basic() {
 
     println!("Thinning summary: {}", summary);
 
-    // Should have thinned at least 1 large tool result in the first third
+    // Should show the new format with percentage change
-    assert!(
+    assert!(summary.contains("g3:"), "Summary was: {}", summary);
-        summary.contains("1 tool result"),
+    assert!(summary.contains("thinning context"));
-        "Summary was: {}",
+    assert!(summary.contains("[done]"));
-        summary
-    );
-    assert!(summary.contains("50%"));
 
     // Check that the large tool results were replaced
     let first_third_end = context.conversation_history.len() / 3;
@@ -134,8 +131,10 @@ fn test_thin_write_file_tool_calls() {
 
     println!("Thinning summary: {}", summary);
 
-    // Should have thinned the write_file tool call
+    // Should show the new format with percentage change
-    assert!(summary.contains("tool call") || summary.contains("chars saved"));
+    assert!(summary.contains("g3:"));
+    assert!(summary.contains("thinning context"));
+    assert!(summary.contains("[done]"));
 
     // Check that the large content was replaced with a file reference
     let first_third_end = context.conversation_history.len() / 3;
@@ -194,8 +193,10 @@ fn test_thin_str_replace_tool_calls() {
 
     println!("Thinning summary: {}", summary);
 
-    // Should have thinned the str_replace tool call
+    // Should show the new format with percentage change
-    assert!(summary.contains("tool call") || summary.contains("chars saved"));
+    assert!(summary.contains("g3:"));
+    assert!(summary.contains("thinning context"));
+    assert!(summary.contains("[done]"));
 
     // Check that the large diff was replaced with a file reference
     let first_third_end = context.conversation_history.len() / 3;
@@ -227,7 +228,9 @@ fn test_thin_context_no_large_results() {
     let (summary, _chars_saved) = context.thin_context(None);
 
     // Should report no large results found
-    assert!(summary.contains("no large tool results or tool calls found"));
+    assert!(summary.contains("g3:"));
+    assert!(summary.contains("thinning context"));
+    assert!(summary.contains("[no changes]"));
 }
 
 #[test]
@@ -255,9 +258,9 @@ fn test_thin_context_only_affects_first_third() {
     context.used_tokens = 5000;
     let (summary, _chars_saved) = context.thin_context(None);
 
-    // First third is 4 messages (indices 0-3), so only indices 1 and 3 should be thinned
+    // Should show the new format with percentage change
-    // That's 2 tool results
+    assert!(summary.contains("g3:"));
-    assert!(summary.contains("2 tool results"));
+    assert!(summary.contains("[done]"));
 
     // Check that messages after the first third are NOT thinned
     let first_third_end = context.conversation_history.len() / 3;

crates/g3-core/tests/test_todo_context_thinning.rs

@@ -139,11 +139,10 @@ fn test_non_todo_results_still_thinned() {
 
     println!("Thinning summary: {}", summary);
 
-    // Should have thinned the non-TODO result
+    // Should show the new format with percentage change (indicating thinning happened)
-    assert!(
+    assert!(summary.contains("g3:"), "Non-TODO results should be thinned");
-        summary.contains("1 tool result") || summary.contains("chars saved"),
+    assert!(summary.contains("thinning context"));
-        "Non-TODO results should be thinned"
+    assert!(summary.contains("[done]"));
-    );
 
     // Check that the result was actually thinned
     let first_third_end = context.conversation_history.len() / 3;