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/teams/team-fullstack.yaml

@@ -0,0 +1,12 @@
+# <!-- Powered by BMAD-CORE™ -->
+bundle:
+  name: Team Plan and Architect
+  icon: 🚀
+  description: Team capable of project analysis, design, and architecture.
+agents:
+  - analyst
+  - architect
+  - pm
+  - sm
+  - ux-designer
+party: "./default-party.csv"