fix: Add Doxygen docs and remove temporary CI filter

- Add Doxygen documentation to new methods, members, constants, and
  macros introduced by the TSAN/ASAN PR (Database::startReadThreads,
  BasicApp::DeferStart, ResourceManager::start, XRPL_SANITIZER_ACTIVE,
  coroStackSize, yieldStackSize)
- Add @note thread-safety tags where atomics were introduced
- Update Database constructor docs to reflect deferred thread startup
- Remove temporary CI filter that restricted builds to sanitizer-only
  variants (must run full matrix before merge)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/scripts/strategy-matrix/generate.py

@@ -324,17 +324,6 @@ def generate_strategy_matrix(all: bool, config: Config) -> list:
                 }
             )
 
-    # TEMPORARY: Only build previously-failing sanitizer variants to save CI.
-    # Remove this filter once these configs pass.
-    sanitizer_only = [
-        c
-        for c in configurations
-        if c["sanitizers"]
-        and ("gcc-13" in c["config_name"] or "clang-20" in c["config_name"])
-    ]
-    if sanitizer_only:
-        return sanitizer_only
-
     return configurations