docs: add copilot instructions for project development (#412)

Added comprehensive documentation file (.github/copilot-instructions.md) that provides detailed guidance on the Dokploy Open Source Templates project structure, development workflow, and conventions. The document covers the project overview, key files and directories, development workflow for adding/updating templates, local development setup, CI/CD processes, and established conventions and patterns. This documentation will help onboard new contributors and ensure consistent development practices across the project.

.github/copilot-instructions.md

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+# Dokploy Open Source Templates - Copilot Instructions
+
+## Project Overview
+
+This repository maintains Docker Compose templates for deploying open-source applications via Dokploy, a self-hosted PaaS alternative to Heroku. The core structure revolves around the `blueprints/` directory, where each subdirectory represents a deployable service (e.g., `blueprints/ghost/` for Ghost blogging platform).
+
+Key components:
+
+- **Blueprints**: Self-contained templates with `docker-compose.yml` (service definitions) and `template.toml` (Dokploy-specific configuration for domains, env vars, mounts).
+- **meta.json**: Centralized index of all templates, aggregated from blueprint metadata. Entries include `id`, `name`, `version`, `description`, `logo`, `links`, and `tags`.
+- **app/**: Vite-based React frontend for local preview/development (runs at http://localhost:5173). Copies blueprints and meta.json to dist during build.
+- **Scripts**: Node.js tools in root and `build-scripts/` for maintaining `meta.json` (deduplication, sorting, validation).
+
+Data flow: New templates added to `blueprints/` → Metadata updated in `meta.json` → Processing scripts ensure consistency → App builds include static blueprints/meta for preview.
+
+The "why": Enables rapid, standardized deployment of 200+ OSS apps on Dokploy without manual config. Structure prioritizes simplicity—each blueprint is independent, no shared state or complex interdependencies.
+
+## Key Files and Directories
+
+- `meta.json`: Array of template objects. Always process after edits using `node dedupe-and-sort-meta.js` to remove duplicates (by `id`) and sort alphabetically.
+- `blueprints/<service>/`:
+  - `docker-compose.yml`: Standard Docker Compose v3.8. Avoid `ports`, `container_name`, `networks`—Dokploy handles isolation via internal networks.
+  - `template.toml`: Defines variables (e.g., `${domain}`), domains (service:port → host), env vars, and mounts. Use helpers like `${password:32}`, `${uuid}`, `${jwt:secret_var}`.
+  - `logo.svg/png`: Service icon, referenced in `meta.json`.
+- `app/vite.config.ts`: Configures build to copy `blueprints/*` and `meta.json` to dist root for static serving.
+- `dedupe-and-sort-meta.js`: Standalone script—reads `meta.json`, removes duplicate `id`s (keeps first), sorts by `id` (case-insensitive), creates timestamped backup.
+- `build-scripts/process-meta.js`: Advanced processor with CLI options (`--verbose`, `--no-backup`, `--input`/`--output`), JSON schema validation (required: `id`, `name`, `version`, `description`, `links.github`, `logo`, `tags` array).
+
+Exemplary blueprint: `blueprints/ghost/`—`docker-compose.yml` exposes port 2368; `template.toml` maps domain to Ghost service; meta entry tags as ["blogging", "cms"].
+
+## Development Workflow
+
+1. **Add/Update Template**:
+
+   - Create `blueprints/<id>/` (e.g., `ghost`).
+   - Implement `docker-compose.yml` (single service typical; use volumes for persistence).
+   - Configure `template.toml`—reference vars in `[config.domains]`, `[config.env]`, `[config.mounts]`.
+   - Add/update `meta.json` entry with exact `id` matching folder.
+   - Run `node dedupe-and-sort-meta.js --backup` to validate/sort.
+   - Commit; PR triggers Dokploy preview (base64 import for testing).
+
+2. **Local Development**:
+
+   - App: `cd app && pnpm install && pnpm dev` (Vite dev server).
+   - Meta processing: `npm run process-meta` or `make process-meta` (uses Makefile targets: `validate`, `check`, `build`).
+   - Build app: `cd app && pnpm build`—copies blueprints/meta to `dist/` for static hosting.
+   - Test template: Use PR preview URL or local Dokploy instance; import base64 from template card.
+
+3. **CI/CD**:
+   - `.github/workflows/validate-meta.yml` (if present): Runs validation on push/PR—fails on duplicates, invalid JSON, missing fields.
+   - Integrate processing: Add `npm run process-meta` to build steps; use `--no-backup` in CI.
+
+No tests in repo—focus on manual validation via scripts and Dokploy deploys. Debug: Check console output from processing scripts for warnings (e.g., missing `id`).
+
+## Conventions and Patterns
+
+- **Template IDs**: Lowercase, kebab-case (e.g., `active-pieces`); unique across repo—enforced by dedupe script.
+- **Docker Compose**: Minimal—omit `ports` (Dokploy proxies), `restart: unless-stopped`, persistent volumes (e.g., `- db-data:/var/lib/postgresql/data`). Services named after folder (e.g., `ghost` service).
+- **template.toml**:
+  - Variables: `[variables] main_domain = "${domain}"`; use helpers for secrets (`${password:64}`, `${base64:32}`).
+  - Domains: `[[config.domains]] serviceName = "<service>" port = 80 host = "${main_domain}"` (path="/" optional).
+  - Env: `[[config.env]]` array of "KEY=VALUE" strings, interpolating vars (e.g., "DB_PASSWORD=${db_pass}").
+  - Mounts: `[[config.mounts]] filePath = "/etc/config" content = """multi-line\ncontent"""`.
+  - JWT helper: `${jwt:secret_var:payload_var}` for auth tokens; payload as JSON string with `exp: ${timestamps:YYYY-MM-DDTHH:mm:ssZ}`.
+- **Meta.json**: Entries as JSON objects; tags array of lowercase strings (e.g., ["monitoring", "database"]); links object with `github`, `website`, `docs`.
+- **No Networks**: Rely on Dokploy's isolated deployments—avoid explicit `networks:`.
+- **Versions**: Pin images to specific versions in `docker-compose.yml` (e.g., `ghost:5.82.0-alpine`); match in `meta.json.version`.
+- **Logos**: SVG preferred; size ~128x128; file name in `meta.json.logo` (e.g., "ghost.svg").
+
+Cross-component: No runtime communication—templates independent. App consumes static blueprints/meta for UI rendering (e.g., search, cards via React components in `app/src/`).
+
+## Integration Points
+
+- **Dokploy**: Templates import via base64 (full compose + config) or URL. Test deploys validate env interpolation, domain proxying.
+- **External Deps**: Docker Compose (v3.8+); TOML parsing via `@iarna/toml` in app. No runtime deps beyond Node/pnpm for dev.
+- **PR Previews**: Auto-generated on GitHub—use for end-to-end testing without local Dokploy.
+
+When editing, always re-run meta processing and validate blueprint deploy in preview.