docs(repo): BEE-1798 reorganize docs tree + add environments snapshot

[alfredrc]

Summary

• Group docs by intent: api/ (what server exposes), ops/ (how it's operated), observability/ (runtime). New docs/README.md as index.
• Capture current dev↔prod state in docs/ops/environments.md — Cloud Run revisions, service accounts, secrets, CORS config, plus 5 riesgos detectados (prod sin Terraform, sin SA dedicado, sin secrets de beepbox, etc.).
• Fix missing .env/.env.local/.env.*.local entries in .gitignore — these were not gitignored at all.

Tree

docs/
├── README.md                   ← new
├── IDEAS.md                    ← stays at root (global convention)
├── PENDING.md                  ← stays at root (global convention)
├── api/
│   ├── reference.md            (was api.md)
│   └── openapi.yaml
├── ops/
│   ├── infrastructure.md
│   ├── environments.md         ← new snapshot
│   ├── deploy-runbook.md
│   └── supply-chain.md
└── observability/
    ├── metrics.md
    └── tracing.md              (was observability.md)

References updated

• docs/api/reference.md → fixed docs/openapi.yaml path
• docs/PENDING.md → fixed 2× docs/deploy-runbook.md paths
• scripts/validate-openapi.sh → SPEC path
• .github/workflows/openapi-clients.yml → 3× docs/openapi.yaml paths
• git mv used everywhere → history preserved

Test plan

• bash scripts/validate-openapi.sh → OpenAPI spec is valid (path resolution OK after move)
• grep -rn final → cero referencias rotas a paths antiguos
• CI green on this PR (specifically the OpenAPI workflow which now points to docs/api/openapi.yaml)

Closes BEE-1798

🤖 Generated with Claude Code