Several friction points when installing OnlyOffice via install-onlyoffice.sh (Docker deployment)

**Several friction points when installing OnlyOffice via install-onlyoffice.sh (Docker deployment)**

Follow-up to cryptpad/documentation#156 — after getting the base CryptPad instance running, I went on to install OnlyOffice (for the Document/Spreadsheet/Presentation apps) following the Docker instructions.
It completed successfully in the end, but hit a few issues worth flagging.
Here are Claude's comments:

---

**1. The license-review step fails with a 404, blocking installation entirely unless you know the workaround**

`ask_for_license()` fetches the license text from:
```
https://raw.githubusercontent.com/ONLYOFFICE/web-apps/master/LICENSE.txt
```
This currently returns a 404 (the file appears to have moved, or the branch reference is stale), so the script opens `less` on an empty result and hangs waiting for input with nothing to review. It's not obvious from the output that this is a broken upstream URL rather than a genuine script hang — I initially thought the terminal had frozen.

The script does support skipping this via a pre-set `ACCEPT_LICENSE` environment variable, which is a reasonable workaround, but:
- This escape hatch isn't mentioned in the admin guide's OnlyOffice installation section, so a first-time installer has no way to discover it without reading the script source directly.
- Even with the workaround, it'd be worth fixing the underlying URL (or pointing at a pinned tag/commit instead of `master`, which seems to be what actually broke) so the intended license-review flow works as designed for people who don't pass `ACCEPT_LICENSE`.

**2. Permission denied on `onlyoffice-conf`/`onlyoffice-dist`, for the same UID-4001 reason as the main data folders — but not flagged at this step specifically**

The main installation guide does document chowning `data`, `customize`, `onlyoffice-dist`, and `onlyoffice-conf` to UID 4001 upfront if you create these folders before first starting the container. However, if you add OnlyOffice as a *later* step (as I did — get CryptPad running first, add OnlyOffice afterward), it's easy to create the two new folders fresh via a host user account and miss that they need the same UID-4001 ownership as everything else. The failure surfaces well into the install process:
```
./install-onlyoffice.sh: line 134: /cryptpad/onlyoffice-conf/onlyoffice.properties: Permission denied
```
...after the script has already spent a few minutes downloading and unpacking OnlyOffice's editor components, which is a frustrating point to discover a permissions issue. A pre-flight check at the very start of the script (verifying it can actually write to `$CONF_DIR` before doing any downloading) would surface this immediately instead of after a multi-minute download.

**3. A transient DNS resolution failure for `release-assets.githubusercontent.com` (likely not CryptPad's fault, but worth a retry/resilience note)**

Mid-install, the script failed with:
```
curl: (6) Could not resolve host: release-assets.githubusercontent.com (Timeout while contacting DNS servers)
```
This resolved itself on retry a few minutes later, so it was likely a transient issue with GitHub's release-asset CDN or Docker's embedded DNS resolver, not a bug in CryptPad's script. That said, since the script already tracks progress via `onlyoffice.properties` and resumes cleanly from where it left off, it might be worth documenting explicitly ("if a download step fails with a DNS/network error, simply re-run the script — it will skip already-completed steps") so people don't assume a failure here means something is broken.

---

Once past these three points, the install completed cleanly and OnlyOffice's Document/Spreadsheet apps work well, including .docx import. Happy to provide more detail on any of these if useful.