repos-devtools-server: gitignore .env, systemd unit template, README run modes

**Motivations:**
- Document user systemd and keep secrets out of git

**Root causes:**
- N/A

**Correctifs:**
- N/A

**Evolutions:**
- .env gitignored; systemd/user template and README

**Pages affectées:**
- services/repos-devtools-server/.gitignore
- services/repos-devtools-server/README.md
- services/repos-devtools-server/systemd/user/*

services/repos-devtools-server/.gitignore

@@ -1,2 +1,3 @@
 node_modules/
 dist/
+.env

services/repos-devtools-server/README.md

@@ -21,12 +21,23 @@ All endpoints require `Authorization: Bearer <REPOS_DEVTOOLS_TOKEN>`.
 
 ## Run
 
+### One-off (foreground)
+
 ```bash
 cd services/repos-devtools-server
 npm install
 npm run build
-export REPOS_DEVTOOLS_TOKEN='generate-a-long-random-secret'
+# Create .env (gitignored) with REPOS_DEVTOOLS_TOKEN=... and REPOS_DEVTOOLS_ROOT=/home/ncantu/code
-npm start
+set -a && source .env && set +a && node dist/server.js
+```
+
+### systemd (user)
+
+Copy `systemd/user/repos-devtools-server.service` to `~/.config/systemd/user/`, create `.env` beside this README, then:
+
+```bash
+systemctl --user daemon-reload
+systemctl --user enable --now repos-devtools-server.service
 ```
 
 Use the same token in the VS Code / Cursor setting **`anythingllm.reposApiToken`**.

services/repos-devtools-server/systemd/user/README.md

@@ -0,0 +1,8 @@
+# User systemd unit
+
+1. Create `../.env` (see main README): `REPOS_DEVTOOLS_TOKEN`, `REPOS_DEVTOOLS_ROOT`.
+2. `mkdir -p ~/.config/systemd/user`
+3. `cp repos-devtools-server.service ~/.config/systemd/user/`
+4. `systemctl --user daemon-reload && systemctl --user enable --now repos-devtools-server.service`
+
+Adjust `WorkingDirectory`, `EnvironmentFile`, and `ExecStart` paths if the repository is not at `/home/ncantu/code/smart_ide`.

services/repos-devtools-server/systemd/user/repos-devtools-server.service

@@ -0,0 +1,14 @@
+[Unit]
+Description=4NK repos-devtools-server (git API for /home/ncantu/code)
+After=network.target
+
+[Service]
+Type=simple
+WorkingDirectory=/home/ncantu/code/smart_ide/services/repos-devtools-server
+EnvironmentFile=/home/ncantu/code/smart_ide/services/repos-devtools-server/.env
+ExecStart=/usr/bin/node dist/server.js
+Restart=on-failure
+RestartSec=3
+
+[Install]
+WantedBy=default.target