## Approach
- Read existing files before writing. Don't re-read unless changed.
- Thorough in reasoning, concise in output.
- Skip files over 100KB unless required.
- No sycophantic openers or closing fluff.
- No emojis or em-dashes.
- Do not guess APIs, versions, flags, commit SHAs, or package names. Verify by reading code or docs before asserting.

## Global
- Utilise Docker & Docker-Compose pour la base de données (MariaDB)
- On développe tout en NodeJS notamment avec : NextJS & Prisma pour la partie backend et React pour la partie frontend
- Utilise Tailwind pour le CSS
- L'application est toujours multilangue (EN + FR)

## Application : Ombrora-YTDLP

- Interface web publique permettant de soumettre des URLs de videos a telecharger via yt-dlp.
- Les telechargements sont geres via une file d'attente (queue) executee par Passenger en arriere-plan avec support du multithreading.
- Chaque telechargement est stocke en base de donnees (MariaDB via Prisma). **Aucune entree n'est jamais supprimee** : la DB conserve l'historique complet de tous les telechargements (statuts, erreurs, metadata).
- Le worker Passenger est responsable de dequeuer et d'executer yt-dlp en parallele selon la capacite configuree.

## Deployment (o2switch)

- o2switch is shared hosting: no compiler toolchain, no root access. Any dependency with a native/binary component must ship as a precompiled binary — it cannot be built from source on the server.
- Before adding any new dependency with native bindings, confirm it publishes prebuilt binaries for o2switch's platform/arch — otherwise it will fail to install or run there.
- **The o2switch nodevenv/Passenger setup ("Setup Node.js App" in cPanel) only supports a single `package.json`/`node_modules` for the whole registered app — not one per subfolder.** Verified by directly debugging a failed `frontend/` build: `npm install --prefix frontend --include=dev` (root's own `build` script) and even a plain `npm install` run with `cd frontend` first (confirmed via `pwd` to genuinely be inside `frontend/`) both completed "successfully" (correct, unmodified `frontend/package-lock.json`, real `resolved` entries for every package) yet never created a `frontend/node_modules` directory on the server at all. Meanwhile `vite`/`@vitejs/plugin-react` (already present as root devDependencies) resolved fine during the build — only packages that exist *exclusively* in `frontend/package.json` (`react-router-dom`, `react-i18next`, `i18next`, `@phosphor-icons/react`) failed to resolve, with Vite/Rolldown erroring `Rolldown failed to resolve import "react-router-dom"`.
    - **Fix (applied):** every runtime package `frontend/src/**` imports must also be listed in the **root** `package.json`'s `dependencies` (not just `frontend/package.json`'s) — `react`/`react-dom` already were; `react-router-dom`, `react-i18next`, `i18next`, `@phosphor-icons/react` were added there too. Root's single `node_modules` is an ancestor directory of `frontend/src/`, so Node/Vite's normal upward `node_modules` resolution walk finds them there even with no `frontend/node_modules` on the server.
    - `frontend/package.json` still declares the same packages in its own `dependencies` — that's intentional, not stale duplication. It's what makes local dev (`npm run dev` inside `frontend/`, which gets a real, normal `frontend/node_modules` on a dev machine) work independently of this server-only constraint. When adding a new frontend runtime dependency, add it to **both** `package.json` files (frontend's own, for local dev; root's, for the o2switch build) and run `npm install` in both places to keep both lockfiles in sync.
    - `frontend/package.json`'s `devDependencies` (`vite`, `@vitejs/plugin-react`, `oxlint`, `@types/react*`) do **not** need mirroring to root — only the ones already there (`vite`, `@vitejs/plugin-react`) are actually required for the production build to run at all; `oxlint`/`@types/*` are dev-only tooling never invoked during `npm run build`.

<!-- BEGIN:nextjs-agent-rules -->

# This is NOT the Next.js you know

This version has breaking changes — APIs, conventions, and file structure may all differ from your training data. Read the relevant guide in `node_modules/next/dist/docs/` (resolved from this file's directory; in monorepos the `next` package may not be visible from the repo root) before writing any code. Heed deprecation notices.

This block is written and re-added by `next dev` — verify at `node_modules/next/dist/server/lib/generate-agent-files.js`. Removing it from a diff only re-creates the uncommitted change; committing it with your work keeps the tree clean.

<!-- END:nextjs-agent-rules -->

<!-- code-review-graph MCP tools -->
## MCP Tools: code-review-graph

**IMPORTANT: This project has a knowledge graph. ALWAYS use the
code-review-graph MCP tools BEFORE using Grep/Glob/Read to explore
the codebase.** The graph is faster, cheaper (fewer tokens), and gives
you structural context (callers, dependents, test coverage) that file
scanning cannot.

### When to use graph tools FIRST

- **Exploring code**: `semantic_search_nodes` or `query_graph` instead of Grep
- **Understanding impact**: `get_impact_radius` instead of manually tracing imports
- **Code review**: `detect_changes` + `get_review_context` instead of reading entire files
- **Finding relationships**: `query_graph` with callers_of/callees_of/imports_of/tests_for
- **Architecture questions**: `get_architecture_overview` + `list_communities`

Fall back to Grep/Glob/Read **only** when the graph doesn't cover what you need.

### Key Tools

| Tool | Use when |
|------|----------|
| `detect_changes` | Reviewing code changes — gives risk-scored analysis |
| `get_review_context` | Need source snippets for review — token-efficient |
| `get_impact_radius` | Understanding blast radius of a change |
| `get_affected_flows` | Finding which execution paths are impacted |
| `query_graph` | Tracing callers, callees, imports, tests, dependencies |
| `semantic_search_nodes` | Finding functions/classes by name or keyword |
| `get_architecture_overview` | Understanding high-level codebase structure |
| `refactor_tool` | Planning renames, finding dead code |

### Workflow

1. The graph auto-updates on file changes (via hooks).
2. Use `detect_changes` for code review.
3. Use `get_affected_flows` to understand impact.
4. Use `query_graph` pattern="tests_for" to check coverage.