docker: don't pin playwright, split: system deps + firefox after npm install

`npx playwright install --with-deps firefox` fails since package.json references 1.29 but current version is 1.30:
`browserType.launchPersistentContext: Executable doesn't exist at /root/.cache/ms-playwright/firefox-1369/firefox/firefox`

Need to either pin the version there or install the browser after `npm install` which will make it take into account the package.json version.
See microsoft/playwright#13188, microsoft/playwright#12835

Image size:

1. 1.12GB - `npx playwright install --with-deps firefox` -> fails due to wrong browser version
2. 1.12GB - `npx [email protected] install --with-deps firefox` -> pinning version works, but need to also update Dockerfile when updating package.json
3. 920MB - `npx playwright install-deps firefox` -> fails, system deps only, no browser
4. 1.12GB - 3. + `npx install firefox` after `npm install` -> works, no pinning needed, system deps stuff is cleaned up with the rest of the apt installs; breaks if system deps change...

Author: vogler

Dockerfile

@@ -23,7 +23,7 @@ RUN apt-get update \
       novnc websockify \
       dos2unix \
       python3-pip \
-    && npx playwright@1.29 install --with-deps firefox \
+    && npx playwright install-deps firefox \
     && apt-get clean \
     && rm -rf \
       /tmp/* \
@@ -38,7 +38,8 @@ RUN pip install apprise
 WORKDIR /fgc
 COPY package*.json ./
 
-RUN npm install
+# If firefox is installed (~/.cache/ms-playwright/firefox-*) before `npm install` it may be a newer version than in package.json and playwright will not find it; system deps are installed sep. via apt above to avoid having to pin the version there.
+RUN npm install && npx playwright install firefox
 
 COPY . .