Add QET 2.0 refactoring initiative to History page

- Document code refactoring goals and rationale
- Explain file format evolution (.elmt → .selmt, .qet → SQLite structure)
- Detail architectural improvements (ActionPool, persistence layer, conductor system)
- Add context: Joshua inherited project with technical debt in 2012
- Explain modern design patterns for maintainability

Source: qelectrotech.org/wiki_new/refonte_du_code_de_qelectrotech
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GtMZqGEiUMvDBqcFvVG2vb

SOURCE-HISTORY-INFO.md

@@ -76,3 +76,45 @@ Gathered from: qelectrotech.org, qelectrotech.org/wiki_new/, qelectrotech.org/fo
 - License: GNU/GPL
 - Actively maintained with regular features and translations
 - Version 0.100.1 or 0.200.0 planned with newer Qt6 framework
+
+## From QET Code Refactoring Wiki (refonte_du_code_de_qelectrotech)
+
+### QET 2.0 Refactoring Initiative
+
+This is a major architectural redesign effort to address accumulated technical debt and modernize the codebase.
+
+#### Historical Context
+- **2006** — QET started as a student project with architectural limitations
+- **2012** — Original creator left, Joshua inherited the project
+- **Problem:** "Spaghetti code" and poor modularity accumulated over time
+- **Solution:** Comprehensive refactoring (QET 2.0)
+
+#### Refactoring Goals
+1. Decouple code into distinct, well-separated modules
+2. Remove band-aid solutions
+3. Improve code clarity
+4. Restructure for modern functionality
+5. Enhance maintainability for external contributors
+
+#### Major Technical Changes
+
+**File Format Redesign:**
+- `.elmt` → `.selmt` (with proper SVG namespace)
+- Direct SVG import capability in element editor
+- Separate graphical from non-graphical data (dynamic text, terminals, info)
+
+- `.qet` → **zipped structure with SQLite database**
+  - Simplified .qet file with folio lists and element coordinates
+  - SQLite database for comprehensive metadata
+  - Separate folders for images, elements, title blocks
+  - UUID-based cross-referencing
+
+**Architectural Improvements:**
+- **ActionPool singleton** — Centralize QActions from QetDiagramEditor
+- **Persistence layer abstraction** — Separate serialization from domain logic
+- **Conductor system redesign** — Electrical potential as first-class concept with inheritance
+- **Element prefix standardization** — Unified system
+- **Auto-numbering simplification** — Intelligent formula support
+- **Xref flexibility** — Enhanced cross-reference system
+- **Text rendering** — Switch from points to pixels
+- **Independent text handling** — Simplified structure

history.md

@@ -157,6 +157,34 @@ From basic diagram drawing to:
 - Custom element creation
 - Multi-diagram projects
 
+### QET 2.0 Refactoring Initiative
+
+As QElectroTech matured, accumulated technical debt from the original architecture needed addressing. In **2012**, after the original creator's departure, Joshua and subsequent developers recognized the need for a comprehensive refactoring:
+
+**The Challenge:** Spaghetti code, poor modularity, and band-aid solutions had accumulated over years of development.
+
+**The Solution:** QET 2.0 — A major architectural redesign addressing:
+
+- **Code modularity** — Decouple into distinct, well-separated modules
+- **Action management** — Centralize scattered QActions with an ActionPool singleton
+- **File formats** — Modernize from flat XML to structured, efficient formats
+- **Persistence layer** — Abstract serialization from domain logic
+- **Conductor system** — Introduce electrical potential as a first-class concept
+
+**File Format Evolution:**
+- **Elements:** `.elmt` → `.selmt` (with proper SVG namespace, direct SVG import)
+- **Projects:** `.qet` → Zipped structure with SQLite database for metadata
+- **Structure:** Separate folders for images, elements, title blocks with UUID-based cross-referencing
+
+**Additional Improvements:**
+- Element prefix system standardization
+- Intelligent auto-numbering with formula support
+- Enhanced cross-reference (xref) system
+- Text rendering modernization (points → pixels)
+- Simplified independent text handling
+
+This refactoring represents the project's commitment to long-term maintainability and enabling external contributors to work effectively with the codebase.
+
 ---
 
 ## Future Direction