commit b84807bbdbd0e57fbfc36fcb2602c75d86450569
Author: alexei.dolgolyov <dolgolyov.alexei@gmail.com>
Date:   Sun Apr 5 11:51:39 2026 +0300

    docs: add project plan prompt

diff --git a/PLAN_PROMPT.md b/PLAN_PROMPT.md
new file mode 100644
index 0000000..18799a0
--- /dev/null
+++ b/PLAN_PROMPT.md
@@ -0,0 +1,110 @@
+# House/Apartment Plan Maker — Architecture & Project Plan
+
+## Context
+Greenfield client-server application for creating and editing apartment/house floor plans.
+The repo is empty: `house-plan-maker/`.
+
+## Core Requirements
+1. **Apartment management** — CRUD apartments with metadata (name, address, total area).
+2. **Room editor** — Each apartment contains rooms. Rooms have names, dimensions, and shapes
+   (rectangular default, arbitrary polygon supported).
+3. **Visual editor per room:**
+   - Top-down 2D view (primary editing surface) — place walls, doors, windows, electrical, furniture
+   - 4 side projection views (north/south/east/west walls) — show wall elevation with outlets,
+     switches, furniture against that wall
+   - 3D perspective view (read-only visualization)
+4. **Electrical plan** — Place switches, outlets, junction boxes, light fixtures, cable routes on
+   both top-down and projection views. Use standard IEC electrical symbols.
+5. **Furniture placement** — Drag-and-drop furniture items (bed, desk, wardrobe, sofa, table,
+   chair, shelf, etc.) with approximate dimensions. Visual must be recognizable silhouettes,
+   not photorealistic.
+6. **Persistence** — Save/load apartment data to server (REST API + database).
+7. **Export** — Export full apartment plan or individual room views as PDF or PNG images.
+
+## Assumed Tech Stack (confirm or override)
+- **Frontend:** React 19 + TypeScript + Vite
+- **2D Canvas:** Konva.js via react-konva (layered 2D shapes, drag-and-drop, zoom/pan)
+- **3D View:** Three.js via @react-three/fiber + @react-three/drei
+- **Backend:** Node.js + Fastify + Prisma ORM
+- **Database:** SQLite (dev), PostgreSQL (prod)
+- **PDF Export:** Client-side via jsPDF + html2canvas, or server-side Puppeteer
+- **Monorepo:** Turborepo with `apps/client`, `apps/server`, `packages/shared`
+
+## Target Users
+- **End users:** Plan room layout and furniture placement visually.
+- **Electricians:** Use exported plans to wire the apartment — precise outlet/switch positions matter.
+- **Furniture makers:** Use exported dimensions to build custom furniture.
+
+## Workflow
+1. User creates an apartment → defines rooms (name, shape, dimensions)
+2. User opens a room → edits in 2D top-down view (walls, electrical, furniture)
+3. User switches to projection views to fine-tune wall-mounted items
+4. User previews in 3D
+5. User exports to PDF/PNG
+
+## Deliverable
+Create a phased implementation plan covering:
+- Data model design (apartment → rooms → elements → electrical/furniture)
+- API endpoints
+- Frontend component architecture
+- 2D editor architecture (layers, tools, snapping, grid)
+- Projection view rendering strategy
+- 3D view approach
+- Export pipeline
+- Testing strategy
+
+Break into 4 implementation phases with clear milestones.
+
+## Additional Ideas to Evaluate
+- Snap-to-grid and snap-to-wall for precise placement
+- Measurement annotations (auto-display distances between elements)
+- Room templates (bedroom, kitchen, bathroom presets)
+- Undo/redo stack
+- Layer toggling (show/hide electrical, furniture, dimensions independently)
+- Copy room layout between apartments
+- Cable length calculator based on placed electrical elements
+- Light coverage visualization (radius circles around light fixtures)
+- Collision detection for furniture overlap
+- Scale ruler always visible on canvas
+
+---
+
+## Quick Version
+
+Greenfield app: `house-plan-maker/`. Client-server for creating apartment floor plans.
+
+Stack: React 19 + TS + Vite | react-konva (2D) | react-three-fiber (3D) | Fastify + Prisma + SQLite | Turborepo monorepo.
+
+Features: Apartment → Rooms (rectangular or polygon). Per-room visual editor: 2D top-down + 4 wall projections + 3D preview. Place electrical (IEC symbols: outlets, switches, lights, cables) and furniture (recognizable silhouettes). Save/load via REST API. Export PDF/PNG.
+
+Create a phased implementation plan (4 phases) with data model, API, component architecture, 2D editor design, and export pipeline.
+
+---
+
+## Implementation Phases
+
+### Phase 0 — Architecture & Planning
+- **Model:** Opus
+- **ECC:** `/plan`, `architect` agent
+- Finalize tech stack, data model, API design, component tree, editor architecture
+
+### Phase 1 — Project Scaffold + Data Model + API
+- **Model:** Sonnet
+- **ECC:** `feature-dev`, `api-design`, `tdd-guide`
+- Monorepo setup, Prisma schema, REST endpoints, basic CRUD UI
+
+### Phase 2 — 2D Visual Editor (Top-Down + Projections)
+- **Model:** Sonnet
+- **ECC:** `feature-dev`, `frontend-design`, `code-reviewer`
+- Canvas editor with layers, tools, grid, snapping, drag-and-drop
+- Wall projection views
+
+### Phase 3 — 3D View + Electrical & Furniture Libraries
+- **Model:** Sonnet
+- **ECC:** `feature-dev`, `frontend-patterns`
+- Three.js scene from room data, electrical symbol library, furniture silhouette library
+
+### Phase 4 — Export + Polish
+- **Model:** Sonnet
+- **ECC:** `feature-dev`, `e2e-runner`
+- PDF/PNG export, undo/redo, measurement annotations, layer toggling, final QA