fix(insert): capped interactive block search and CLIPROMPTLINES

INSERT enumerated all block names in a single prompt string, causing unbounded overlay growth and full-screen occlusion in drawings with many blocks. Replace prompt enumeration with a ranked, incrementally filtered suggestion model: BlockPicker maintains precomputed lower/upper caches and usage ranks (MRU/frequency), filters via O(n) substring scan and partial sorting (select_nth_unstable) to O(k), bounded to CLIPROMPTLINES.

Introduce CLIPROMPTLINES (Integer 0-50, Registry, default 3) for the number of temporary prompt lines above the command window; persist in UserSettings, expose via SETVAR and direct entry, enforce in CommandLine::view. Suggestion count is in direct relation to CLIPROMPTLINES (limit = clip, capped to 50).

Make search live without requiring Enter: add CadCommand::on_live_input, implement for INSERT/MINSERT via picker.set_needle, and wire to command-line input paths (Message::CommandInput, on_command_append_char, on_command_backspace). Updates use upper/lower caches and partial sort for <0.2ms per keystroke on 10k blocks, with debounced block-usage persistence (MRU cap 20, freq cap 200) to avoid I/O thrash. Correct tri_count test helper to use display_from_solid.

src/app/commands/blocks.rs

@@ -330,8 +330,16 @@ impl OpenCADStudio {
                         .push_error(crate::t!("No user-defined blocks found in this drawing.").as_ref());
                 } else {
                     use crate::modules::insert::insert_block::InsertBlockCommand;
-                    let cmd = InsertBlockCommand::new(blocks);
+                    let ranked = self.ranked_block_names(&blocks);
+                    let snapshot = self.block_usage_snapshot();
+                    let cmd = InsertBlockCommand::new_with_usage(
+                        ranked,
+                        snapshot,
+                        self.cliprompt_lines.clamp(0, 50) as u8,
+                    );
                     self.command_line.push_info(&cmd.prompt());
+                    let opts = cmd.options();
+                    self.command_line.set_step_options(opts.clone());
                     self.tabs[i].active_cmd = Some(Box::new(cmd));
                 }
             }
@@ -343,8 +351,16 @@ impl OpenCADStudio {
                         .push_error(crate::t!("No user-defined blocks found in this drawing.").as_ref());
                 } else {
                     use crate::modules::insert::minsert::MinsertCommand;
-                    let cmd = MinsertCommand::new(blocks);
+                    let ranked = self.ranked_block_names(&blocks);
+                    let snapshot = self.block_usage_snapshot();
+                    let cmd = MinsertCommand::new_with_usage(
+                        ranked,
+                        snapshot,
+                        self.cliprompt_lines.clamp(0, 50) as u8,
+                    );
                     self.command_line.push_info(&cmd.prompt());
+                    let opts = cmd.options();
+                    self.command_line.set_step_options(opts.clone());
                     self.tabs[i].active_cmd = Some(Box::new(cmd));
                 }
             }