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/workflows/bmad-quick-flow/quick-dev/steps/step-03-execute.md

@@ -0,0 +1,111 @@
+---
+name: 'step-03-execute'
+description: 'Execute implementation - iterate through tasks, write code, run tests'
+
+nextStepFile: './step-04-self-check.md'
+---
+
+# Step 3: Execute Implementation
+
+**Goal:** Implement all tasks, write tests, follow patterns, handle errors.
+
+**Critical:** Continue through ALL tasks without stopping for milestones.
+
+---
+
+## AVAILABLE STATE
+
+From previous steps:
+
+- `{baseline_commit}` - Git HEAD at workflow start
+- `{execution_mode}` - "tech-spec" or "direct"
+- `{tech_spec_path}` - Tech-spec file (if Mode A)
+- `{project_context}` - Project patterns (if exists)
+
+From context:
+
+- Mode A: Tasks and AC extracted from tech-spec
+- Mode B: Tasks and AC from step-02 mental plan
+
+---
+
+## EXECUTION LOOP
+
+For each task:
+
+### 1. Load Context
+
+- Read files relevant to this task
+- Review patterns from project-context or observed code
+- Understand dependencies
+
+### 2. Implement
+
+- Write code following existing patterns
+- Handle errors appropriately
+- Follow conventions observed in codebase
+- Add appropriate comments where non-obvious
+
+### 3. Test
+
+- Write tests if appropriate for the change
+- Run existing tests to catch regressions
+- Verify the specific AC for this task
+
+### 4. Mark Complete
+
+- Check off task: `- [x] Task N`
+- Continue to next task immediately
+
+---
+
+## HALT CONDITIONS
+
+**HALT and request guidance if:**
+
+- 3 consecutive failures on same task
+- Tests fail and fix is not obvious
+- Blocking dependency discovered
+- Ambiguity that requires user decision
+
+**Do NOT halt for:**
+
+- Minor issues that can be noted and continued
+- Warnings that don't block functionality
+- Style preferences (follow existing patterns)
+
+---
+
+## CONTINUOUS EXECUTION
+
+**Critical:** Do not stop between tasks for approval.
+
+- Execute all tasks in sequence
+- Only halt for blocking issues
+- Tests failing = fix before continuing
+- Track all completed work for self-check
+
+---
+
+## NEXT STEP
+
+When ALL tasks are complete (or halted on blocker), read fully and follow: `{project-root}/_bmad/bmm/workflows/bmad-quick-flow/quick-dev/steps/step-04-self-check.md`.
+
+---
+
+## SUCCESS METRICS
+
+- All tasks attempted
+- Code follows existing patterns
+- Error handling appropriate
+- Tests written where appropriate
+- Tests passing
+- No unnecessary halts
+
+## FAILURE MODES
+
+- Stopping for approval between tasks
+- Ignoring existing patterns
+- Not running tests after changes
+- Giving up after first failure
+- Not following project-context rules (if exists)