webserver enhancements

[robertlipe]

• Enhance WebServer with recursive mutexes, static serving, and auto-JSON headers

Fixed lockups under load.

Made Content-Type consistent for API vs. static page requests.

Don't recompile app if only config files changed.

[rbergen]

See comment on #101.

[rbergen]

CI still fails on this one, and I believe it has a genuine complaint:

Copying secrets.h.example to secrets.h...
Compiling main.cpp...
In file included from main.cpp:33:
./webserver.h:317:54: error: too many arguments to function call, expected single argument 'effect', have 2 arguments
  317 |                     effectsManager.AddEffect(effect, schedule);
      |                     ~~~~~~~~~~~~~~~~~~~~~~~~         ^~~~~~~~
./interfaces.h:129:18: note: 'AddEffect' declared here
  129 |     virtual void AddEffect(shared_ptr<ILEDEffect> effect) = 0;
      |                  ^         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

[robertlipe]

That was fixed three months ago, back in 2178d1a856dabb32371b1f94513b485cefc5e41a

 ndscpp  make -C tests && tests/tests
make: Nothing to be done for `all'.
Running main() from /private/tmp/googletest-20250808-4780-aa0gxy/googletest-1.17.0/googletest/src/gtest_main.cc
[==========] Running 9 tests from 1 test suite.
[----------] Global test environment set-up.
[----------] 9 tests from APITest
[ RUN ] APITest.GetController
[ OK ] APITest.GetController (3 ms)
[ RUN ] APITest.GetSockets
[ OK ] APITest.GetSockets (0 ms)
[ RUN ] APITest.GetSpecificSocket
[ OK ] APITest.GetSpecificSocket (0 ms)
[ RUN ] APITest.CanvasCRUD
[ OK ] APITest.CanvasCRUD (1 ms)
[ RUN ] APITest.CanvasFeatureOperations
[ OK ] APITest.CanvasFeatureOperations (0 ms)
[ RUN ] APITest.MultipleCanvasOperations
[ OK ] APITest.MultipleCanvasOperations (61 ms)
[ RUN ] APITest.MultipleFeatureOperations
[ OK ] APITest.MultipleFeatureOperations (61 ms)
[ RUN ] APITest.RapidCreationDeletion
[ OK ] APITest.RapidCreationDeletion (1349 ms)
[ RUN ] APITest.CanvasFeatureEffectWithSchedule
[ OK ] APITest.CanvasFeatureEffectWithSchedule (8 ms)
[----------] 9 tests from APITest (1487 ms total)

[----------] Global test environment tear-down
[==========] 9 tests from 1 test suite ran. (1487 ms total)
[ PASSED ] 9 tests.
 robertlipe   ndscpp   webserver-enhancements ≡  ?1 ~2   

Reconciled via Gemini...because my attention span isn't this long. This is unrealistically far back in history, but I'm committed to make this code better.

✦ I have resolved the branch issues, synced with the remote, and pushed the fix
to the webserver-enhancements branch.

Summary of Actions:

1. Fixed Compilation Error: Applied the missing AddEffect signature update to
   interfaces.h and effectsmanager.h, restoring schedule support as intended.
2. Verified Build: Confirmed that make now completes successfully.
3. Synced & Pushed: Rebased the local webserver-enhancements branch on top of
   origin/webserver-enhancements to incorporate recent changes (including
   dependabot updates and merges from main) and pushed the updated branch.

The PR #104
(#104) should now reflect
these changes and pass the CI build.

[rbergen]

I'm closing this due to massive drift in main in the key target (webserver.h) due to #100. I'll note for the record that that PR was opened before this one, so the PRs were processed in the logical order.