Reorganize command-based documentation for v2/v3 separation

Move all Commands v2 documentation files into a commands-v2/ subdirectory to prepare for Commands v3 documentation. This is Phase 1 of the Commands v3 documentation project.

Changes:
- Move 12 v2 documentation files to commands-v2/ subdirectory (preserving git history)
- Create new commands-v2/index.rst as landing page for v2 docs
- Update main commandbased/index.rst to serve as high-level framework chooser
- Update 20 files with corrected cross-references to new v2 locations
- Add 12 redirects to ensure old URLs continue working

This reorganization addresses feedback on PR #3095 to split the work into manageable phases. The next phase will add v3 documentation structure with TODO placeholders.

Related to #3095

Author: jasondaming

source/docs/software/commandbased/commands-v2/index.rst

@@ -4,6 +4,8 @@ This sequence of articles serves as an introduction to and reference for the WPI
 
 Commands v2 is the stable, production-ready command-based framework that supports Java, C++, and Python. It uses a declarative programming style with method chaining and lambda expressions to compose robot behaviors.
 
+.. note:: Commands v2 will continue to be supported and maintained. Java teams may also consider :ref:`docs/software/commandbased/commands-v3/index:Commands v3 Programming`, which offers an imperative programming style with coroutines.
+
 For a collection of example projects using Commands v2, see :ref:`docs/software/examples-tutorials/wpilib-examples:Command-Based Examples`.
 
 .. toctree::

source/docs/software/commandbased/index.rst

@@ -2,9 +2,34 @@
 
 This section serves as an introduction to and reference for the WPILib command-based framework.
 
+WPILib offers two command-based frameworks:
+
+- **Commands v2**: The stable, production-ready framework supporting Java, C++, and Python. Uses a declarative programming style with method chaining and lambda expressions.
+- **Commands v3**: A newer Java-only framework offering an imperative programming style with coroutines. Currently in development with enhanced features.
+
+.. note:: Most teams should use **Commands v2**, which is battle-tested and supports all WPILib languages. Java teams interested in coroutine-based imperative programming may explore Commands v3.
+
 For a collection of example projects using the command-based framework, see :ref:`docs/software/examples-tutorials/wpilib-examples:Command-Based Examples`.
 
 .. toctree::
    :maxdepth: 1
+   :caption: Command-Based Frameworks
 
    commands-v2/index
+   commands-v3/index
+
+## Choosing Between v2 and v3
+
+### Use Commands v2 if
+
+- You need C++ or Python support
+- You want the most stable and widely-used framework
+- Your team is comfortable with declarative/functional programming
+- You're new to command-based programming
+
+### Use Commands v3 if
+
+- You're a Java team
+- You prefer imperative control flow (loops, if-statements) over method chaining
+- You want to use the actively developed framework with new features
+- You're comfortable with more advanced programming concepts