feat: Enable image rendering and enhanced document editing (#4)

.gitignore

@@ -1,5 +1,5 @@
 /out/
-/node_modules/
+node_modules/
 /.vscode-test/
 *.vsix
 .DS_Store

CHANGELOG.md

@@ -4,31 +4,42 @@ All notable changes to the "PengSheets" extension will be documented in this fil
 
 ## [Unreleased]
 
+### Added
+
+- Native image support in Document tabs with paste and drag-and-drop capabilities.
+- Integrated EasyMDE for enhanced Markdown editing in Document tabs.
+
 ## [1.3.0] - 2026-03-11
 
 ### Added
+
 - Support YAML frontmatter with `title` field as an H1 equivalent, following a widely adopted convention.
 - Display a read-only header field above the editor in Document tab edit mode, showing the Markdown heading level (e.g. `## Title`).
 
 ### Fixed
+
 - Fix empty table cells containing extra whitespace (`|  |` → `| |`).
 - Fix extra blank lines accumulating under Document tab headers on each cell edit in frontmatter workbooks.
 
 ## [1.2.1] - 2026-02-24
 
 ### Fixed
+
 - Fix Doc tab in Single H1 workbook showing table icon and spreadsheet toolbar instead of file icon and no toolbar.
 - Fix edit mode for all Document tabs displaying `# title` header in textarea. Header is now omitted since tab name is editable via double-click.
 - Fix edit mode textarea opening scrolled to bottom instead of top.
 
 ## [1.2.0] - 2026-02-23
+
 ### Changed
+
 - **Simplified Workbook Detection**: Documents with a single H1 header are now automatically recognized as a Workbook. The previous convention of using `# Tables` as the Workbook marker is no longer required. Documents with multiple H1 headers continue to work as before (backward compatible).
 - **Overview Tab**: Content directly under the H1 header is now displayed as a dedicated "Overview" tab. This tab supports renaming and deletion via context menu.
 
 ## [1.1.0] - 2026-01-22
 
 ### Added
+
 - **Formula Columns**: A powerful new feature for automatic calculations and cross-table lookups
   - **Calculation mode**: Apply formulas to columns using arithmetic expressions (`[Price] * [Quantity]`) or aggregate functions (SUM, AVG, COUNT, MIN, MAX). *Note: Currently limited to columns within the same table.*
   - **Table Lookup mode**: VLOOKUP-style cross-table references to pull values from other tables
@@ -39,61 +50,73 @@ All notable changes to the "PengSheets" extension will be documented in this fil
   - **Error Detection**: Non-numeric values in calculations return N/A for easy detection of broken references
 
 ### Fixed
+
 - Fix sheet reordering across interleaved documents being incorrectly treated as physical-only moves, causing metadata removal and incorrect document order.
 - Fix document save button not working.
 
 ## [1.0.6] - 2026-01-11
 
 ### Fixed
+
 - Fix column names not saving when edited: The `updateCell` function now correctly handles header row edits (`rowIdx = -1`).
 
 ## [1.0.5] - 2026-01-11
 
 ### Fixed
+
 - Fix context menu and add-tab dropdown being clipped when displayed near viewport edges.
 - Fix + button "Add New Document" inserting document at wrong position in hybrid notebooks.
 - Fix certain UI operations (e.g., toolbar formatting, column drag-and-drop) not updating immediately when document is unsaved.
 
 ## [1.0.4] - 2026-01-10
 
 ### Fixed
+
 - Fix multiline text deletion in edit mode: Delete/Backspace now correctly removes selected text spanning newlines in contenteditable cells.
 - Fix split-view layout corruption when deleting tables: Table indices in layout metadata are now properly updated after table deletion.
 - Fix visual flicker when pressing Delete key on selected cells: Skip re-parsing workbook during synchronous updates to preserve optimistic UI changes.
 
 ### Added
+
 - Add Selection/Range API mock for comprehensive JSDOM testing of contenteditable behavior.
 - Add "Delete Pane" button (×) to empty split-view panes with improved empty state UI.
 
 ### Improved
+
 - Significantly improved startup speed by replacing Pyodide with native WASM integration.
 
 ## [1.0.3] - 2026-01-07
 
 ### Fixed
+
 - Fix document edit mode not being cancelled when clicking on bottom tabs.
 
 ### Improved
+
 - Add scroll spacer at the end of document view for better scrolling experience.
 
 ## [1.0.2] - 2026-01-05
 
 ### Fixed
+
 - Eliminate the blank period during extension startup by optimizing the loading indicator's CSS positioning (`position: fixed`).
 - Update the underlying `md-spreadsheet-parser` to v1.1.0, improving performance and stability.
 
 ## [1.0.1] - 2026-01-05
 
 ### Added
+
 - Add context menu item "Edit Table Description" to table tabs.
 - Implement metadata editor for editing table descriptions.
 
 ### Fixed
+
 - Fix loading timing issues where the extension could hang on initialization.
 
 ## [1.0.0] - 2026-01-03
 
 ### Added
+
 - Initial release of PengSheets.
 - Provides a spreadsheet-like GUI for editing Markdown tables.
 - Supports validation, formatting, and rich editing features.

package.json

@@ -240,7 +240,10 @@
         "vitest": "^4.0.15"
     },
     "dependencies": {
+        "easymde": "^2.20.0",
+        "highlight.js": "^11.11.1",
         "js-yaml": "^4.1.1",
+        "marked-highlight": "^2.2.3",
         "md-spreadsheet-parser": "^1.4.3"
     }
 }