# Claude Code Journal

This journal tracks substantive work on documents, diagrams, and documentation content.

---

1. **Task - Project initialization**: Created project-specific CLAUDE.md configuration and journal tracking system<br>
   **Result**: Added `.claude/CLAUDE.md` with JupyterLab 4.x extension context, TypeScript 5.8 stack, development commands, and package naming conventions; initialized `.claude/JOURNAL.md` for tracking substantive work

2. **Task - VSCode icons integration**: Integrated @iconify-json/vscode-icons package (1414 icons) into JupyterLab extension using proper docRegistry API<br>
   **Result**: Installed @iconify-json/vscode-icons npm package; created `src/icons.ts` with extension-to-icon mappings and SVG resolution utilities; implemented `src/index.ts` with `docRegistry.addFileType()` and `LabIcon` creation from Iconify JSON data; replaced initial DOM manipulation approach with proper JupyterLab file type registration

3. **Task - Icon alias resolution**: Fixed icon resolution for aliased icons in Iconify data structure<br>
   **Result**: Updated `getIconSVG()` function in `src/icons.ts` to check aliases first, then resolve parent icon references; handles two-level indirection where alias points to parent icon, and parent icon may reference another parent

4. **Task - Settings system implementation**: Added configurable icon groups with toggle controls via JupyterLab settings<br>
   **Result**: Created `schema/plugin.json` with 6 boolean settings (enableLanguageIcons, enableWebIcons, enableDataIcons, enableConfigIcons, enableDocIcons, enableImageIcons); implemented settings integration with ISettingRegistry in `src/index.ts`; added file type grouping by category in fileTypeConfigs array; implemented dynamic registration based on enabled groups

5. **Task - File type coverage expansion**: Added comprehensive file type support including shell scripts, git files, package managers, and build tools<br>
   **Result**: Added .bat, .cmd, .ps1 (Windows shell scripts) to shell icon group; added .vbs, .vbe (VBA scripts) with VBA icon; added pattern matching for .git, .gitignore, .gitmodules, .gitattributes files; added LICENSE file variants pattern; added .lnk (Windows shortcuts); added package manager configs (package.json, yarn.lock, requirements.txt, Cargo.toml, Gemfile); added Dockerfile and .dockerignore pattern matching

6. **Task - README documentation**: Updated README with shameless VSCode-icons ripoff theme and configuration instructions<br>
   **Result**: Rewrote README.md with humorous "shameless ripoff" messaging; added Features section listing 6 icon groups; added Configuration section explaining settings toggles; added proper attribution to vscode-icons project and Iconify; removed development sections per user request

7. **Task - Makefile icon implementation**: Added custom Makefile support with red "M" icon using pattern from jupyterlab*makefile_file_type_extension, removed JSON/YAML from VSCode icon configs to preserve JupyterLab defaults<br>
   **Result**: Implemented separate Makefile file type registration with custom SVG icon (red "M" text); added mimeTypes ['text/x-makefile'] and comprehensive pattern matching (Makefile, makefile, GNUmakefile, makefile.*, Makefile.\_); registered icon with name "makefile-icon"; removed JSON and YAML from fileTypeConfigs to allow JupyterLab native icons for these formats

8. **Task - TOML icon correction**: Fixed pyproject.toml displaying Python icon instead of TOML icon<br>
   **Result**: Changed iconName from 'file-type-python' to 'file-type-toml' in line 315 of `src/index.ts`; pyproject.toml now displays gray "T" icon instead of blue/yellow Python logo; version updated to 1.0.13

9. **Task - Jupytext icon override attempt via docRegistry**: Attempted to override Jupytext's notebook icons for .py and .md files using docRegistry.addFileType with override parameter<br>
   **Result**: Failed - re-registering file types with same names ('python', 'markdown') and ['notebook'] override parameter had no effect; Jupytext's icons remained dominant; discovered that file type icon property is read-only, preventing direct assignment like `(pyTypes[0] as any).icon = pythonIcon`

10. **Task - Jupytext icon override attempt via file type removal**: Attempted to remove Jupytext's python and markdown file types from registry to allow VSCode icons to take precedence<br>
    **Result**: Failed - removing file types from `docRegistry._fileTypes` array caused "File Type markdown not found" errors; other parts of Jupytext still referenced these file types; approach abandoned as too brittle and error-prone

11. **Task - Jupytext icon override attempt via direct icon modification**: Attempted to modify file type objects' icon properties directly after registration<br>
    **Result**: Failed - while console logs showed icon properties were being modified in the file type objects, the file browser UI did not refresh to reflect changes; file browser had already rendered with cached icon references; modifying objects post-render doesn't trigger UI updates in JupyterLab's rendering pipeline

12. **Task - Jupytext icon override attempt via CSS with wrong selectors**: Attempted CSS override targeting `data-file-type="python"` and `data-file-type="markdown"` attributes<br>
    **Result**: Failed - CSS selectors targeted wrong attributes; actual DOM inspection revealed files had `data-file-type="notebook"` not "python" or "markdown"; prompted deep investigation into why file type attribute was set to "notebook" for .py/.md files

13. **Task - LICENSE custom copyright icon**: Designed and implemented custom copyright icon for LICENSE files to replace default key icon<br>
    **Result**: Created custom SVG with blue circle outline and C character path in `src/index.ts` (lines 506-524); registered separate file type 'vscode-license' with pattern matching for LICENSE, LICENCE, and their variants with extensions; icon centered properly with file browser alignment; replaces "corny" key icon from vscode-icons set; version updated through 1.0.14-1.0.17 with centering adjustments

14. **Task - Settings schema configuration**: Fixed 404 error when loading extension settings schema<br>
    **Result**: Added `schemaDir: "schema"` to package.json jupyterlab configuration section (line 100); JupyterLab now correctly locates schema/plugin.json file in installed labextension; settings panel loads without errors; version updated to 1.0.19

15. **Task - Settings alert debouncing**: Fixed multiple alert popups when resetting all settings to defaults<br>
    **Result**: Implemented debounce timer (500ms) in settings change handler (lines 527-567 in `src/index.ts`); when multiple settings change rapidly (like resetting 6 boolean toggles), timer clears and resets on each change; single alert appears 500ms after last change; prevents alert spam when batch-updating settings; version updated to 1.0.20

16. **Task - Jupytext icon override deep source investigation**: Conducted comprehensive source code analysis to understand root cause of icon override failure<br>
    **Result**: **Investigation Process** - Cloned jupytext repository to `/tmp/jupytext`; analyzed `packages/jupyterlab-jupytext-extension/src/tokens.ts` showing FILE_TYPES array includes 'python' and 'markdown' (lines 30-38); analyzed `packages/jupyterlab-jupytext-extension/src/factory.ts` showing NotebookWidgetFactory creation with fileTypes parameter including python and markdown (lines 42, 56-59). Cloned jupyterlab repository to `/tmp/jupyterlab`; analyzed `packages/docregistry/src/registry.ts` revealing critical `getFileTypeForModel()` function (lines 666-704) with special case handling for `model.type === 'notebook'` that returns notebook file type regardless of file extension; analyzed `packages/filebrowser/src/listing.ts` showing file browser rendering that extracts icon from fileType and sets `data-file-type` attribute from `fileType.name` (lines 3281, 3393). **Root Cause Discovery** - Jupytext server extension modifies file contents API responses to mark .py and .md files with `model.type = 'notebook'` (not 'file'); when JupyterLab's `getFileTypeForModel()` sees `model.type === 'notebook'`, it immediately returns the notebook file type with `name: "notebook"` without checking file extension; file browser renders these files with `data-file-type="notebook"` attribute; this server-side type override happens before client-side file type resolution, making conventional file type registration approaches ineffective. **Key Insight** - The issue occurs at the file model level (server-side), not at the file type registration level (client-side); any solution must work around the already-rendered DOM with `data-file-type="notebook"` attribute rather than trying to change the file type assignment itself

17. **Task - Jupytext icon override final solution**: Implemented DOM-based icon override for Python files using CSS injection and MutationObserver to show VSCode Python icon instead of Jupytext notebook icon<br>
    **Result**: **The Problem** - Jupytext server marks .py files with `model.type = 'notebook'`; JupyterLab's `getFileTypeForModel()` sees this and returns notebook file type; file browser renders with `data-file-type="notebook"` attribute; conventional file type registration cannot override this because the type assignment happens server-side before client-side rendering. **The Solution** - Created `injectIconOverrideCSS()` function (lines 372-468 in `src/index.ts`) that works at DOM/CSS layer. **How It Works** - (1) JavaScript detects .py files: MutationObserver watches file browser for changes; when it finds items with `data-file-type="notebook"`, it checks filenames; adds `data-jupytext-py="true"` attribute to .py files. (2) CSS hides Jupytext icon and shows VSCode icon: Targets `[data-file-type="notebook"][data-jupytext-py]` selector; hides existing notebook icon with `display: none !important`; injects VSCode Python icon via `::before` pseudo-element with base64-encoded SVG data URI. **Why This Works** - Operates at presentation layer (DOM/CSS), not data layer (file types); doesn't conflict with Jupytext's server-side `model.type` assignment; doesn't break Jupytext notebook functionality; survives file browser navigation through MutationObserver. **Markdown Files** - User prefers JupyterLab/Jupytext default markdown icon over VSCode markdown icon; no override applied to .md files; they keep notebook icon. **Version** - Python icon override in 1.0.21; markdown preference in 1.0.23

18. **Task - Markdown icon with JupyterLab native icon**: Updated solution to override Jupytext notebook icon for markdown files with JupyterLab's native markdown icon (not VSCode's)<br>
    **Result**: User requested original JupyterLab markdown icon (not Jupytext notebook icon, not VSCode markdown icon); imported `markdownIcon` from `@jupyterlab/ui-components`; updated `injectIconOverrideCSS()` function to handle both Python and Markdown files; Python files get VSCode Python icon; Markdown files get JupyterLab native markdown icon; both override Jupytext's notebook icon using same CSS + MutationObserver pattern; version updated to 1.0.25

19. **Task - JavaScript icon brightness adjustment**: Reduced brightness of JavaScript file icons using CSS filters<br>
    **Result**: Added CSS filter to JavaScript icons (`brightness(0.85) saturate(0.85)`) to make them less bright; applied to all JavaScript file types (.js, .mjs, .cjs) via data-file-type selectors; version updated to 1.0.26; tagged as STABLE_1.0.26

20. **Task - LICENSE icon emboldening**: Made LICENSE file icon more prominent with thicker strokes<br>
    **Result**: Increased circle stroke-width from 2 to 3; added subtle stroke (stroke-width: 0.5) to C path for better definition; version 1.0.26

21. **Task - README badges and GitHub workflows update**: Updated README with comprehensive badge set and synchronized GitHub Actions workflows with reference repository<br>
    **Result**: Added 6 badges to README (GitHub Actions, npm version, PyPI version, PyPI downloads, JupyterLab 4 compatibility, KOLOMOLO branding); updated all 6 workflow files (.github/workflows/) based on reference repository jupyterlab_makefile_file_type_extension; added link checker ignore patterns for badge URLs (`ignore_links: "https://www.npmjs.com/package/.* https://pepy.tech/.* https://static.pepy.tech/.*"`); code formatting with Prettier and ESLint applied to all TypeScript and CSS files; renamed interfaces to follow TypeScript conventions (IconSettings -> IIconSettings, FileTypeConfig -> IFileTypeConfig); fixed CSS selector ordering in style/base.css; version 1.0.26

22. **Task - Shell script icon colorization**: Applied color filters to differentiate Linux and Windows shell script icons<br>
    **Result**: Separated shell file configuration - Linux shells (.sh, .bash, .zsh) use 'file-type-shell' icon with pale red filter (`hue-rotate(340deg) saturate(0.6) brightness(1.1)`); Windows shells (.bat, .cmd, .ps1) use 'file-type-powershell' icon with pale blue filter (`hue-rotate(180deg) saturate(0.5) brightness(1.2)`); CSS filters added to injectIconOverrideCSS function; version updated to 1.0.28; tagged as STABLE_1.0.28

23. **Task - Claude icon for CLAUDE.md files**: Added special icon support for CLAUDE.md configuration files<br>
    **Result**: Added pattern-based file type registration for `CLAUDE\\.md$` using vscode-icons 'file-type-claude' icon; pattern matches CLAUDE.md in any directory (uses basename matching); placed in enableDocIcons group after markdown registration; CLAUDE.md files display Claude branding icon instead of generic markdown icon; version 1.0.29

24. **Task - Code cleanup and repository configuration**: Removed debug console.log statements and configured package.json for GitHub workflows<br>
    **Result**: Removed 5 console.log statements from `src/index.ts` (activation message, CSS injection logs, file type registration logs, settings loading logs); added repository URL, homepage, and bugs URL to package.json for GitHub Actions compatibility; fixed CSS selector specificity order in style/base.css (moved `.jp-BreadCrumbs` before higher-specificity selectors); added Jupytext compatibility note to README.md features list; version 1.0.29

25. **Task - Shell icon unification and CLAUDE.md pattern fix**: Unified .bat/.cmd files to use same shell icon as .sh files with different colors; fixed CLAUDE.md pattern matching<br>
    **Result**: Changed .bat and .cmd to use 'file-type-shell' icon (same as .sh/.bash/.zsh) instead of 'file-type-powershell' rhombus icon; kept .ps1 with powershell icon; implemented MutationObserver-based coloring using data-shell-type attributes (data-shell-type="linux" for .sh/.bash/.zsh, data-shell-type="windows" for .bat/.cmd); Linux shells display pale red (`hue-rotate(320deg) saturate(0.8) brightness(1.0)`); Windows shells display pale blue (`hue-rotate(180deg) saturate(0.6) brightness(1.2)`); extended markSpecialFiles() function to mark both Jupytext files and shell files; fixed CLAUDE.md pattern to `^CLAUDE\\.md$` with registration before general .md extension for proper precedence; updated ui-tests to verify extension loads via docRegistry check instead of console message; version 1.0.30

26. **Task - CLAUDE.md icon CSS override implementation**: Fixed CLAUDE.md icon display by implementing CSS-based override (same approach as Jupytext files)<br>
    **Result**: Discovered CLAUDE.md detected as `data-file-type="notebook"` by Jupytext, preventing pattern-based registration from working; implemented CSS override solution - added CLAUDE.md detection in markSpecialFiles() MutationObserver (sets `data-claude-md="true"` attribute when filename exactly matches "CLAUDE.md"); injected Claude icon via CSS ::before pseudo-element with base64-encoded SVG data URI from createLabIcon('file-type-claude'); hides original notebook icon with `display: none !important`; adjusted .sh icon color to inverted palette with desaturated red (`invert(1) hue-rotate(130deg) saturate(0.8) brightness(0.9)`); added debug console logging for CLAUDE.md registration; CLAUDE.md now displays orange/coral Claude logo icon instead of notebook icon; version 1.0.30; tagged as STABLE_1.0.30

27. **Task - README.md custom icon and purple color scheme**: Added custom info icon for README.md files and applied purple color (#9826c8) to both README.md and CLAUDE.md icons<br>
    **Result**: Created custom README.md icon - purple filled circle with white bold lowercase "i" text inside; implemented same CSS override approach as CLAUDE.md (MutationObserver detects "README.md" exactly, sets `data-readme-md="true"` attribute, CSS hides notebook icon and injects custom SVG via ::before); applied purple tint to CLAUDE.md icon using CSS filter (`hue-rotate(270deg) saturate(1.5) brightness(1.1)`); both icons now use consistent #9826c8 purple color; version 1.0.31

28. **Technical Documentation - Filename-specific icon styling approach**: Documented the solution for styling individual filenames differently in JupyterLab<br>
    **Challenge**: JupyterLab's docRegistry pattern matching (`pattern: '^FILENAME\\.ext$'`) doesn't work when Jupytext or other extensions override file type detection at the server level (e.g., marking .md files as `model.type='notebook'`); `getFileTypeForModel()` in docRegistry returns notebook type before client-side pattern matching occurs; conventional file type registration approach ineffective for files already classified by server-side extensions<br>
    **Solution Discovery Process**: Initial attempts - tried pattern-based registration with various pattern formats ('^CLAUDE\\.md$', 'CLAUDE\\.md$', basename matching); tried registering before/after general .md extension; tried removing extensions parameter; all failed because Jupytext marks files as notebooks server-side. HTML inspection revealed `data-file-type="notebook"` attribute instead of expected pattern-matched type. Breakthrough - realized need to work at DOM/presentation layer rather than data/registration layer<br>
    **Working Solution (3-step process)**: (1) MutationObserver watches file browser DOM - observes `.jp-DirListing-content` with `{childList: true, subtree: true}` to detect file list changes; queries all `.jp-DirListing-item[data-file-type="notebook"]` items; reads filename from `.jp-DirListing-itemText` span; exact string match (e.g., `name === 'CLAUDE.md'`) to identify target files; sets custom data attribute `item.setAttribute('data-claude-md', 'true')` for CSS targeting. (2) CSS hides original icon - targets via combined selectors `.jp-DirListing-item[data-file-type="notebook"][data-claude-md]`; hides existing icon with `display: none !important` on both svg and img children; prevents notebook icon from showing. (3) CSS injects replacement icon - uses `::before` pseudo-element on `.jp-DirListing-itemIcon`; creates base64 data URI from SVG (`data:image/svg+xml;base64,${btoa(svgString)}`); displays via `background-image: url('...')` with contain sizing; applies CSS filters for color adjustments if needed. **Key Technical Details**: MutationObserver runs continuously to handle navigation/refresh; must handle both initial load (setTimeout) and dynamic changes (observer callback); works around server-side type assignment that happens before client-side file type resolution; operates at presentation layer (DOM/CSS) rather than data layer (docRegistry); doesn't break functionality of underlying file type (notebook still opens correctly); survives file browser navigation and directory changes. **Example Implementation Pattern**: markSpecialFiles() function called on initial load and by MutationObserver; single function handles multiple special filenames (CLAUDE.md, README.md, .py/.md Jupytext notebooks, .sh/.bat shell scripts for coloring); CSS organized by purpose (Jupytext overrides, special filename overrides, color filters); base64 encoding performed once during CSS injection, not per file. **Use Cases**: Works for any filename that needs different styling than its extension would normally provide; particularly useful when server-side extensions (Jupytext, nbclassic, etc.) override file types; enables file-specific branding (CLAUDE.md with Claude icon, README.md with info icon); allows per-file color customization while sharing base icon

29. **Task - README.md icon refinements**: Fine-tuned README.md icon boldness through multiple iterations to achieve optimal visual balance<br>
    **Result**: Implemented transparent "i" cutout using SVG mask technique where lowercase "i" appears as hole in purple circle allowing background to show through; changed font to Courier New monospace; adjusted sizing and boldness across versions 1.0.32-1.0.37 - started with 18px circle radius 11, white "i"; increased to 20px, radius 14, added transparency with mask; iterated on boldness with font sizes 22px->21px->20px and stroke-widths 1.5->1->0.7; final version 1.0.37 uses font size 20px, stroke-width 0.7px, radius 12px for optimal readability; maintained purple color #9826c8; provides better visual integration with both light and dark JupyterLab themes; tagged as STABLE_1.0.37

30. **Task - Release documentation and publishing**: Updated release notes, changelog, package metadata, and published to PyPI<br>
    **Result**: Updated RELEASE.md with comprehensive version 1.0.37 notes including features, technical details, related features, and compatibility information; updated CHANGELOG.md with all versions from 1.0.19 through 1.0.37 organized by features/enhancements/bug fixes/maintenance; corrected package.json repository URL from ".git" to full GitHub URL; published package to PyPI as version 1.0.38; tagged STABLE_1.0.37 and pushed to remote

31. **Task - Custom SVG icons replacement**: Replaced static image icons with custom SVG versions for Python, Markdown, and README files<br>
    **Result**: Python icon - replaced with simplified official logo (50% reduced fidelity) using gradients (#387EB8 to #366994 for blue snake, #FFE052 to #FFC331 for yellow snake) and rounded coordinates, preserving snake eyes; Markdown icon - created custom purple (#7a2491, darker shade) design with down-arrow chevron shape and large "M" letter using path data from markdown.svg; README icon - created custom info icon with purple (#8f4397, slightly darker) rounded square background and bolder "i" symbol using path data from info2.svg; all icons embedded as inline SVG in src/index.ts replacing VSCode icon library references; updated README.md Credits section with note about hand-crafted icons in Inkscape; version 1.0.43

32. **Task - Dynamic icon scaling compatibility**: Updated custom icon CSS to scale proportionally with UI font size changes<br>
    **Result**: Replaced hardcoded pixel sizes (18px, 20px) in custom icon ::before pseudo-elements with dynamic CSS calculations using `calc(var(--jp-ui-font-size1, 13px) * var(--jp-custom-icon-scale, 1.5))`; applies to Python, Markdown, CLAUDE.md, and README.md icons injected via CSS background-image; icons now scale proportionally when using jupyterlab_change_ui_font_size_fix extension; maintains consistent sizing with other file browser icons across different font size settings; fallback values ensure icons display correctly even without font size fix extension installed; version 1.0.44

33. **Task - Icon swapping fix and hidden folder styling**: Fixed icon swapping issue during folder navigation and enhanced hidden folder visibility<br>
    **Result**: Icon swapping fix - added `removeAttribute()` calls to clear all previous special file attributes (data-claude-md, data-readme-md, data-jupytext-py, data-jupytext-md) before setting new attributes in markSpecialFiles() function; prevents DOM element reuse from causing attribute persistence across folder navigation; resolves issue where icons and colors changed when moving between folders; Hidden folder styling - added CSS opacity rules targeting `.jp-mod-hidden` class; hidden folder icons set to 25% opacity, text to 30% opacity using `.jp-DirListing-item.jp-mod-hidden` selectors; makes hidden folders (starting with .) significantly darker than regular folders for better visual differentiation; both fixes improve icon stability and file browser UX; version 1.0.46

34. **Task - Hidden items opacity adjustment**: Corrected hidden folder/file opacity implementation using data-is-dot attribute selector and CSS file placement<br>
    **Result**: Changed from `.jp-mod-hidden` class selector to `[data-is-dot]` attribute selector which correctly targets items starting with dot; moved opacity rule from JavaScript-injected CSS to style/base.css for proper loading; set opacity to 55% (changed from percentage to decimal format, then back to 55% at user request); applies to all hidden items (files and folders starting with .); shell script icon brightness increased from 0.9 to 1.1 for better visibility; version 1.0.48

35. **Task - Icon centering and color standardization**: Fixed horizontal centering for all file browser icons and standardized shell script and .env file colors<br>
    **Result**: Added `justify-content: center;` to `.jp-DirListing-item .jp-DirListing-itemIcon` in style/base.css for proper horizontal alignment of all icons including custom README.md icon; replaced shell script hue-rotate filters with direct JupyterLab orange color using precise filter chain (`brightness(0) saturate(100%) invert(58%) sepia(76%) saturate(3113%) hue-rotate(1deg) brightness(101%) contrast(101%)`); corrected .env file type selector from `vscode-file-type-env` to `vscode-file-type-dotenv` to properly apply JavaScript brightness filter (`brightness(0.85) saturate(0.85)`) for consistent yellow tone across config files; version 1.0.56

36. **Task - Icon color persistence fix**: Resolved icon color/style swapping issue during folder navigation by clearing all special attributes from all items<br>
    **Result**: Modified `markSpecialFiles()` function to clear all custom data attributes (`data-shell-type`, `data-claude-md`, `data-readme-md`, `data-jupytext-py`, `data-jupytext-md`) from ALL `.jp-DirListing-item` elements at the start of function execution; prevents DOM element reuse from causing files (like TOML) to inherit style attributes from previously rendered files (like shell scripts); ensures clean state before re-applying attributes based on current file types; version 1.0.58

37. **Task - Defensive attribute handling**: Fixed persistent icon color swapping where JavaScript, PNG, and TOML files incorrectly displayed shell script orange filter<br>
    **Result**: Changed CSS selectors to require BOTH `data-file-type="vscode-file-type-shell"` AND `data-shell-type="linux/windows"` attributes for shell script color filters to apply; completely refactored `markSpecialFiles()` function to actively remove incorrect attributes instead of just clearing all upfront - function now iterates through all items, checks current `data-file-type` attribute, and removes `data-shell-type` if item is not a shell file type; only sets `data-shell-type` when both file type AND file extension match shell script patterns; same defensive logic applied to notebook attributes; prevents race conditions where JupyterLab updates `data-file-type` after observer runs but attributes persist on reused DOM elements; version 1.0.60

38. **Task - Notebook attribute isolation**: Fixed .py files sometimes displaying README.md info icon due to attribute persistence<br>
    **Result**: Modified notebook file handling to clear all notebook attributes (`data-claude-md`, `data-readme-md`, `data-jupytext-py`, `data-jupytext-md`) BEFORE setting the correct attribute based on filename; prevents DOM element reuse from causing .py files to retain `data-readme-md` attribute when DOM element previously rendered README.md; ensures only one notebook attribute is set per item at any time; version 1.0.62

39. **Task - CLAUDE.md icon color update**: Changed CLAUDE.md icon to Claude brand color #c77c5e<br>
    **Result**: Replaced purple hue-rotate filter with precise filter chain targeting Claude's orange/coral color #c77c5e (`brightness(0) saturate(100%) invert(64%) sepia(35%) saturate(647%) hue-rotate(327deg) brightness(91%) contrast(87%)`); CLAUDE.md files now display with authentic Claude brand color; version 1.0.64

40. **Task - README.md icon update and npm icon desaturation**: Updated README.md icon with latest info2.svg path and desaturated npm icons<br>
    **Result**: Updated README.md icon with corrected path from info2.svg file (using fillet-chamfer effect version with better rounded corners); color remains #912bac; added CSS filter to desaturate and dim npm package icons (`brightness(0.85) saturate(0.75)`) to reduce white brightness and overall color intensity; version 1.0.67

41. **Task - Debug code cleanup**: Removed debug console.log statements from source code<br>
    **Result**: Removed all debug console.log statements for CLAUDE.md and README.md file type registration; kept console.error for error handling; cleaner production code without debug output; version 1.0.70

42. **Task - MS Office and PDF icons initial attempt**: Added icons for Microsoft Office files and PDF override using file type registration<br>
    **Result**: Added file type registrations for Word (.doc, .docx), Excel (.xls, .xlsx), and PowerPoint (.ppt, .pptx) using vscode-icons file-type-word, file-type-excel, and file-type-powerpoint icons; attempted CSS override for PDF files targeting `data-file-type="pdf"` attribute; version 1.0.71; approach failed - JupyterLab native file types take precedence over extension registrations

43. **Task - MS Office and PDF icons MutationObserver override**: Implemented proper PDF and Office icon overrides using MutationObserver pattern (same approach as Jupytext files)<br>
    **Result**: Replaced simple file type registration approach with DOM-based override; extended markSpecialFiles() function to detect PDF and Office files by extension; added custom data attributes (`data-vscode-pdf`, `data-vscode-word`, `data-vscode-excel`, `data-vscode-powerpoint`); CSS hides native icons and injects VSCode icons via ::before pseudo-element with base64-encoded SVG data URIs; dynamically sized using `calc(var(--jp-ui-font-size1, 13px) * var(--jp-custom-icon-scale, 1.5))`; defensive attribute clearing prevents DOM element reuse issues; supports .pdf, .doc, .docx, .xls, .xlsx, .ppt, .pptx extensions; version 1.0.73

44. **Task - Custom PDF icon**: Replaced VSCode PDF icon with custom embedded SVG from .resources/PDF_icon.svg<br>
    **Result**: Embedded simplified PDF icon directly in src/index.ts - document shape with folded corner, red banner with white "PDF" text; changed document fill from white (#fff) to light gray (#e8e8e8) for better visibility in both light and dark themes; removed dependency on vscode-icons file-type-pdf; version 1.0.76

45. **Task - Custom Makefile icon**: Replaced red "M" text icon with document-with-gears SVG from .resources/text-x-makefile-svgrepo-com.svg<br>
    **Result**: Embedded document icon with two gears (color #c2544f) in src/index.ts; adjusted viewBox to `19 7 90 114` removing spacing around shape; updated pattern matching to exact match `^(Makefile|makefile|GNUmakefile)$` - removed `makefile.*` and `Makefile.*` patterns as those could be other file types; kept extensions `.mk`, `.mak`, `.make`; version 1.0.81

46. **Task - Terraform icons**: Added Terraform file type support with vscode-icons file-type-terraform icon<br>
    **Result**: Added extensions `.tf`, `.tfvars`, `.tfstate`; added pattern matching for `terraform.tfvars.*`, `.terraform.lock.*`, `.terraform.tfstate.lock.*`; all in enableConfigIcons group; version 1.0.84
