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>

.gitignore

@@ -0,0 +1,24 @@
+# AI tool output (planning artifacts are excluded from git)
+_bmad-output/
+
+# PlatformIO build artifacts
+.pio/
+
+# Environment overrides
+.env.local
+.env.*.local
+
+# Symfony runtime
+var/
+storage/images/
+
+# Composer
+vendor/
+
+# macOS
+.DS_Store
+
+# IDE
+.idea/
+.vscode/
+*.swp