Frontend build improvements, hopefully fix Fomantic build

[silverwind]

• add package-lock.json to webpack/fomantic prereqs making them always rebuild when dependencies change.
• remove FOMANTIC_EVIDENCE. It seemed better to just track a few output files instead.
• delete fomantic output files before build to prevent possible bugs in fomantic's build.
• resolve WEBPACK_SOURCES only once for performance
• reorder variables for clarity
• use clean-all in Dockerfile
• detect busybox for find syntax

Fixes: #10569
Fixes: #10565
Fixes: #10570
Fixes: #10568

[silverwind]

Prereq tracking still seems fine after this, e.g. I can run make fomantic && make fomantic or make webpack && make webpack and the second one skips on my machine in all cases.

[silverwind]

Added $(NODE_MODULES_EVIDENCE) in place of node_modules. I think it's unfortunately inevitable to use such a file because when tools write into node_modules, its timestamp may not accurately reflect when it was last updated anymore, which in turn could skip a update of the folder.

The newly added node_modules target is purely for convenience/testing, by the way.

[silverwind]

Still investigating how those broken fomantic builds came to be exactly. https://try.gitea.io/fomantic/semantic.min.css indicates 2.8.4 which means my theory might not have been correct.

[codecov-io]

Codecov Report

Merging #10576 into master will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #10576      +/-   ##
==========================================
+ Coverage   43.72%   43.75%   +0.02%     
==========================================
  Files         585      585              
  Lines       82026    82026              
==========================================
+ Hits        35864    35887      +23     
+ Misses      41724    41706      -18     
+ Partials     4438     4433       -5

Impacted Files	Coverage Δ
modules/indexer/stats/db.go	50% <0%> (-9.38%)	⬇️
models/unit.go	37.03% <0%> (-2.47%)	⬇️
modules/queue/workerpool.go	56.93% <0%> (-1.07%)	⬇️
models/notification.go	64.71% <0%> (+0.83%)	⬆️
modules/queue/unique_queue_disk_channel.go	55.76% <0%> (+1.92%)	⬆️
services/pull/temp_repo.go	31.62% <0%> (+2.56%)	⬆️
services/pull/patch.go	64.51% <0%> (+2.58%)	⬆️
modules/git/command.go	89.56% <0%> (+2.6%)	⬆️
modules/process/manager.go	78.31% <0%> (+3.61%)	⬆️
services/pull/check.go	56.7% <0%> (+6.7%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update aa4a297...16d32ad. Read the comment docs.

[silverwind]

I think this is now ready. Here is what it now does:

• add package-lock.json to webpack/fomantic prereqs making them always rebuild when dependencies change.
• remove FOMANTIC_EVIDENCE. It seemed better to just track a few output files instead.
• delete fomantic output files before build to prevent possible bugs in fomantic's build.
• resolve WEBPACK_SOURCES only once for performance
• reorder variables for clarity

Regarding the UI issues, I'm still not sure what their cause is but it is certainly either something about unclean builds. I did observe that semantic.min.css file was missing like 30kB data when the issue showed, maybe caused by a bug in fomantic's build process, but the removal of output files before the build should help.

[silverwind]

If this doesn't solve the UI issues reliably, the only explanation I have left is that it's an intermittent issue in fomantic 2.8.4 and we should downgrade to 2.8.3. The incomplete fomantic builds don't show on every build, try.gitea.io was affected yesterday, but is okay today.

[silverwind]

Squashed and updated commit message.

[silverwind]

Two more fixups included:

• Use clean-all in Dockerfile so fomantic gets rebuilt in there as well
• Detect busybox to avoid find: unrecognized: -regextype error