Revert "chore(bmad): replace upstream BMAD scaffold with Specter-specific agent framework"

[maggo83]

In one of the past PRs (#21) one commit (b3ba1a2) that reworked the AI agents setup of the team slipped through.
It should have remained local to my own fork.
This revert will undo it and restore the AI agent setup of the playground as before.

[al-munazzim]

Review

LGTM — approve the revert.

What this does

Reverts commit b3ba1a2 from PR #21 which accidentally included a full BMAD agent framework customization (Specter-specific agents, workflows, adapters) that was meant to stay local to maggo83's fork.

Impact

• 942 files changed (413 removed, 410 added, 116 renamed, 3 modified) — looks scary but it's a clean single-commit revert
• Restores the upstream BMAD scaffold (.bmad/bmm/, .bmad/bmb/, .bmad/core/) and removes the Specter-specific agents/workflows
• CLAUDE.md goes back to a simpler version — loses some nice documentation (key file locations, essential commands, i18n rules, MicroPython constraints) but that belonged in the fork, not upstream
• Adds .beads/ directory (beads worktree tooling) — looks intentional/separate from the revert

One thing to note

The reverted CLAUDE.md had genuinely useful project context (build commands, file locations, absolute rules). Might be worth re-adding a lighter version of that in a follow-up, independent of the BMAD framework choice.

Verdict

Clean revert of an accidental commit. No functional code affected (only agent framework config). ✅