Seed approved structure: design SSOT, operator docs, scaffolds.

Product layout for Lumina / Salon_Assistant at 0.1.0-design.
No product implementation until explicit build.

CONTRIBUTING.md

@@ -0,0 +1,35 @@
+# Contributing
+
+## Before you code
+
+1. Read [design/DESIGN_PLAN.md](design/DESIGN_PLAN.md).
+2. Read [design/use-cases.md](design/use-cases.md), [design/scenarios.md](design/scenarios.md), [design/DECISIONS.md](design/DECISIONS.md).
+3. Implementation requires an explicit **build** decision for greenfield features; structural and documentation work follows this CONTRIBUTING guide.
+
+## Platform-first
+
+- Sandbox, policy, credentials, channels, inference: **`nemohermes` / `openshell` only**.
+- Product scripts wrap those CLIs. Do not add a parallel control API.
+
+## Git ops for this product
+
+- Remote: Gitea **Ty_Tech/Salon_Assistant**.
+- Agent Git MCP for this product: **gitea_vps** only (`https://giteamcp1.vps1.afterthedemo.com/mcp`, User-Agent `grok-connectors-manager/`).
+
+## Pull requests
+
+- Branch from `main`.
+- Keep use-case SSOT in `design/use-cases.md` (do not duplicate full matrices in README).
+- Run `make verify` when implementation exists (fixture CI).
+- No secrets in commits.
+
+## Code style
+
+- Python 3.11+ for skill scripts and providers.
+- Deterministic logic in code; LLM only where the design matrix allows.
+
+## Releases
+
+- Tag releases (`vX.Y.Z`).
+- Pin images and MCP package versions in the release manifest.
+- `scripts/upgrade.sh` is the operator upgrade entrypoint (see docs/UPGRADE.md).