feat(table): add TABLEDIT point picking, and consolidate InputKind

- Implement `TABLEDIT` command supporting viewport point-picking on cell interiors
- Support overlapping table hit testing with selection cycling and top-table resolution
- Support `/n` and `\n` multiline paragraph breaks (`\P`) in table cell text editing
- Unify text input modes via `InputKind` (`Point`, `SingleToken`, `FreeText`) on `CadCommand`
- Migrate 15+ commands across annotate, draw, insert, layout, and view modules
- Preserve text casing, literal spaces, and bypass arithmetic eval during FreeText input
- Add dedicated `tabledit_tests` and `free_text_entry_tests` test suites

src/app/mod.rs

@@ -323,6 +323,21 @@ pub enum StartSection {
     Supporters,
 }
 
+/// What the Space / Enter keys currently mean at the command line. One
+/// decision point (`OpenCADStudio::text_entry_mode`) for every keyboard
+/// route that used to re-derive the answer from editor state.
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub(crate) enum TextEntryMode {
+    /// Normal command line: Space submits, Enter finalises.
+    Command,
+    /// MText preview pane: every key is literal content, Enter is a line break.
+    MTextPreview,
+    /// Free-form text prompt (table cell content, TEXT / MTEXT bodies):
+    /// Space is literal, typed case is preserved, Enter finishes the edit,
+    /// Shift+Enter inserts a line break.
+    FreeText,
+}
+
 pub(super) struct OpenCADStudio {
     start: Instant,
     tabs: Vec<DocumentTab>,