docs: clarify security regression guarantees

crates/constraints/src/model.rs

@@ -623,7 +623,7 @@ mod budget_tests {
     use cadcraft_geom::Vec3;
     use std::sync::Arc;
 
-    /// Writing a model back preserves partial rational weights and the spline they describe.
+    /// Writing an unchanged model back leaves partial rational weights and the original spline geometry intact.
     #[test]
     fn write_back_keeps_partial_rational_weights() {
         let mut drawing = Drawing::default();

crates/mcp/src/backend.rs

@@ -185,7 +185,7 @@ fn is_read_only(method: &str) -> bool {
 }
 
 impl Backend for Remote {
-    /// Send an authenticated control request, refreshing the token for a safe retry.
+    /// Send a control request with the token when available, refreshing it before a safe retry.
     /// A mutation that may have reached the server is never resent automatically.
     fn call(&mut self, method: &str, params: Value) -> Result<Value, String> {
         let id = self.next_id;

crates/render/src/linetype.rs

@@ -118,7 +118,7 @@ pub fn ranges(len: f64, lt: &Linetype, scale: f64, min_pattern: f64) -> Option<V
 mod tests {
     use super::*;
 
-    /// A pattern containing only gaps produces no ranges or strokes without cycling through its repeats.
+    /// This gap-only pattern draws nothing, and `ranges` returns before cycling through its repeats.
     #[test]
     fn an_all_gap_pattern_draws_nothing_without_spinning() {
         let lt = Linetype::simple("GAPS", "", &[-0.001, -0.002]);

crates/render/src/table.rs

@@ -412,7 +412,7 @@ mod budget_tests {
         assert!(g.fills.is_empty() && g.texts.is_empty());
     }
 
-    /// A split table clips merge spans using the rendered column count when source columns exceed the limit.
+    /// A split table within the displayed-cell budget clips a merge to contiguous selected rows.
     #[test]
     fn part_clips_merges_using_displayed_column_count() {
         let t = Table {