docs(setup): drop deprecated apt packages on Debian 13 trixie (#223)

## Summary

Follow-up on [#220](#220). [`10-base-packages.sh`](docs/setup/scripts/10-base-packages.sh) fails on a fresh Debian 13 Trixie VM with `E: Impossible de trouver le paquet software-properties-common`. The package is no longer shipped on Trixie — and it was never used by any of our downstream scripts in the first place.

Drop three deprecated / unused packages from the install list. Add an inline comment explaining each kept package's purpose so a drive-by addition doesn't reintroduce the dropped ones.

## What lands

| File | Change |
| --- | --- |
| `docs/setup/scripts/10-base-packages.sh` | Drop `software-properties-common`, `apt-transport-https`, `lsb-release`. Remaining minimal set: `curl wget git ca-certificates gnupg build-essential pkg-config`. Inline comment lists which downstream script consumes each kept package + which three were deliberately removed and why. |
| `docs/setup/01-dev-debian-vm-setup.md` | Step-3 table row for `10-base-packages.sh` updated to match the new package list. |

## Why each removed package wasn't needed

| Package | Why removed |
| --- | --- |
| `software-properties-common` | Drops `add-apt-repository`. We don't use it — [`50-docker.sh`](docs/setup/scripts/50-docker.sh) writes `/etc/apt/sources.list.d/docker.list` manually with the keyring-pinned `signed-by=` form. Also no longer in Trixie. |
| `apt-transport-https` | Transitional package since apt 1.5 (2018) — apt has native HTTPS. Intermittently absent on Trixie. |
| `lsb-release` | Shell scripts read `/etc/os-release` directly (see `50-docker.sh`'s `. /etc/os-release && echo "${VERSION_CODENAME}"`). |

## Unblock path (manual, if you're stuck mid-bootstrap)

The user can either pull this PR and re-run, or shortcut manually:

```bash
sudo apt-get install -y curl wget git ca-certificates gnupg build-essential pkg-config
./docs/setup/scripts/20-zsh.sh   # continue from the next step
```

Scripts are idempotent — re-running `bootstrap.sh` after pulling this PR is also safe.

## Test plan

- [ ] On a fresh Trixie VM, `./docs/setup/scripts/10-base-packages.sh` exits successfully.
- [ ] Verify each downstream script still has the binaries it expects (curl in 40-node.sh, gpg in 50-docker.sh, build-essential in pnpm install, …).
- [x] `pnpm exec prettier --check` clean on the touched files.
- [x] `bash -n docs/setup/scripts/10-base-packages.sh` clean.

---------

Co-authored-by: Julien Gautier <julien.gautier@apf.asso.fr>
Reviewed-on: #223

docs/setup/scripts/10-base-packages.sh

@@ -9,9 +9,23 @@ require_not_root
 log "apt update"
 sudo apt-get update -qq
 
+# Minimal set actually consumed by the other scripts:
+#   - curl/wget    used by 40-node.sh (nvm install), 50-docker.sh (gpg key)
+#                  and the .NET appendix (wget packages-microsoft-prod.deb)
+#   - git          every other script that touches the repo
+#   - ca-certs     HTTPS over apt + curl/wget
+#   - gnupg        verifying the Docker apt repo key
+#   - build-essential / pkg-config — native deps during pnpm install
+#
+# Deliberately NOT installed (deprecated or unused on Debian 13 Trixie):
+#   - software-properties-common: drops `add-apt-repository`, which we
+#     don't use (50-docker.sh writes /etc/apt/sources.list.d/docker.list
+#     manually). Also failing to resolve on a fresh Trixie install.
+#   - apt-transport-https: apt has had native HTTPS support since 1.5 (2018),
+#     the transitional package isn't needed and is intermittently absent.
+#   - lsb-release: shell scripts read /etc/os-release directly (see 50-docker.sh).
 apt_install \
-  curl wget git ca-certificates gnupg lsb-release \
-  software-properties-common apt-transport-https \
+  curl wget git ca-certificates gnupg \
   build-essential pkg-config
 
 ok "Base packages ready."