Refactor documentation approach: use docstrings instead of separate docs

- Remove IntegratorInterface.md and FunctionWrappers.md documentation pages
- Add proper docstrings to function wrapper types in src/function_wrappers.jl:
  * AbstractWrappedFunction, TimeGradientWrapper, UJacobianWrapper
  * TimeDerivativeWrapper, UDerivativeWrapper, ParamJacobianWrapper
  * JacobianWrapper - all with comprehensive documentation
- Add docstrings to integrator cache functions in src/integrator_interface.jl:
  * user_cache, u_cache, du_cache, ratenoise_cache, rand_cache
- Add docstrings to clock trait functions in src/clock.jl:
  * isclock, issolverstepclock, iscontinuous, iseventclock
  * is_discrete_time_domain
- Update pages.jl to remove deleted documentation files
- Documentation builds successfully with proper docstring integration

This follows best practices by documenting the API directly in source code
rather than maintaining separate documentation files.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: ChrisRackauckas

docs/pages.jl

@@ -11,10 +11,8 @@ pages = [
         "interfaces/AlgorithmTraits.md",
         "interfaces/Solutions.md",
         "interfaces/Init_Solve.md",
-        "interfaces/IntegratorInterface.md",
         "interfaces/Ensembles.md",
         "interfaces/EnsembleAnalysis.md",
-        "interfaces/FunctionWrappers.md",
         "interfaces/ClockSystem.md",
         "interfaces/Common_Keywords.md",
         "interfaces/Differentiation.md",

docs/src/interfaces/FunctionWrappers.md

@@ -47,30 +47,60 @@ discrete-time systems that assume a fixed sample time, such as PID controllers a
 filters.
 """ SolverStepClock
 
+"""
+    isclock(clock)
+
+Returns `true` if the object is a valid clock type (specifically a `PeriodicClock`).
+This function is used for type checking in clock-dependent logic.
+"""
 isclock(c::Clocks.Type) = @match c begin
     PeriodicClock() => true
     _ => false
 end
 isclock(::TimeDomain) = false
 
+"""
+    issolverstepclock(clock)
+
+Returns `true` if the clock is a `SolverStepClock` that triggers at every solver step.
+This is useful for monitoring solver progress or implementing step-dependent logic.
+"""
 issolverstepclock(c::Clocks.Type) = @match c begin
     SolverStepClock() => true
     _ => false
 end
 issolverstepclock(::TimeDomain) = false
 
+"""
+    iscontinuous(clock)
+
+Returns `true` if the clock operates in continuous time (i.e., is a `ContinuousClock`).
+Continuous clocks allow events to occur at any real-valued time instant.
+"""
 iscontinuous(c::Clocks.Type) = @match c begin
     ContinuousClock() => true
     _ => false
 end
 iscontinuous(::TimeDomain) = false
 
+"""
+    iseventclock(clock)
+
+Returns `true` if the clock is an `EventClock` that triggers based on specific events.
+Event clocks are used for condition-based triggering in hybrid systems.
+"""
 iseventclock(c::Clocks.Type) = @match c begin
     EventClock() => true
     _ => false
 end
 iseventclock(::TimeDomain) = false
 
+"""
+    is_discrete_time_domain(clock)
+
+Returns `true` if the clock operates in discrete time (i.e., is not a continuous clock).
+Discrete time domains have specific sampling intervals or event-based triggering.
+"""
 is_discrete_time_domain(c::TimeDomain) = !iscontinuous(c)
 
 # workaround for https://github.com/Roger-luo/Moshi.jl/issues/43