feat: initial commit — BMAD tooling, Claude memories, firmware scaffold

Adds the complete project foundation:
- BMAD BMM workflow tooling (_bmad/)
- Claude slash commands, skills, and project memories (.claude/)
- ESP32 firmware scaffold (PlatformIO + Waveshare e-ink driver)
- .gitignore excluding _bmad-output/ and .pio/ build artifacts

Planning artifacts (PRD, architecture, epics) are intentionally not
tracked — they live in _bmad-output/ per project convention.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

_bmad/bmm/3-solutioning/bmad-generate-project-context/project-context-template.md

@@ -0,0 +1,21 @@
+---
+project_name: '{{project_name}}'
+user_name: '{{user_name}}'
+date: '{{date}}'
+sections_completed: ['technology_stack']
+existing_patterns_found: { { number_of_patterns_discovered } }
+---
+
+# Project Context for AI Agents
+
+_This file contains critical rules and patterns that AI agents must follow when implementing code in this project. Focus on unobvious details that agents might otherwise miss._
+
+---
+
+## Technology Stack & Versions
+
+_Documented after discovery phase_
+
+## Critical Implementation Rules
+
+_Documented after discovery phase_