docs: comprehensive documentation overhaul for v2.2.3

Major documentation update bringing all docs current with the 122-tool,
16-category state of the project (previously frozen at v2.1.0-alpha/59 tools).

New documentation (9 files):
- FREEROUTING_GUIDE.md - autorouter setup, Docker/Podman, all 4 tools
- SCHEMATIC_TOOLS_REFERENCE.md - all 27 schematic tools with parameters
- ROUTING_TOOLS_REFERENCE.md - all 13 routing tools with examples
- FOOTPRINT_SYMBOL_CREATOR_GUIDE.md - 8 creator tools with examples
- SVG_IMPORT_GUIDE.md - SVG logo import tool
- DATASHEET_TOOLS_GUIDE.md - datasheet enrichment tools
- PCB_DESIGN_WORKFLOW.md - end-to-end design guide
- ARCHITECTURE.md - system architecture for contributors
- INDEX.md - documentation table of contents

Updated documentation (12 files):
- README.md - tool count 64->122, feature list, contributor credits
- TOOL_INVENTORY.md - complete rebuild with all 122 tools
- STATUS_SUMMARY.md - updated to v2.2.3 feature matrix
- ROADMAP.md - marked completed milestones, added v2.3+ vision
- KNOWN_ISSUES.md - removed resolved issues, added v2.2.x fixes
- CLIENT_CONFIGURATION.md - added KICAD_MCP_DEV, FREEROUTING_JAR env vars
- LIBRARY_INTEGRATION.md - added symbol and project-local library support
- ROUTER_ARCHITECTURE.md, ROUTER_QUICK_START.md - updated tool counts
- IPC_BACKEND_STATUS.md - updated dates
- JLCPCB_USAGE_GUIDE.md - added cross-reference note
- CONTRIBUTING.md - added ARCHITECTURE.md reference, updated tool count

Archived 10 completed planning docs to docs/archive/.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/IPC_BACKEND_STATUS.md

@@ -1,9 +1,9 @@
 # KiCAD IPC Backend Implementation Status
 
 **Status:** Under Active Development and Testing
-**Date:** 2025-12-02
-**KiCAD Version:** 9.0.6
-**kicad-python Version:** 0.5.0
+**Date:** 2026-03-21
+**KiCAD Version:** 9.0+
+**kicad-python Version:** 0.5.0+
 
 ---
 
@@ -209,4 +209,4 @@ python/
 
 ---
 
-**Last Updated:** 2025-12-02
+**Last Updated:** 2026-03-21