feat: enable Windows support by default with Git Bash

- CI now runs both Linux and Windows by default (matrix)
- Updated install.sh to detect Windows venv path (Scripts/ vs bin/)
- Added Windows installation instructions to getting-started.md
- Updated troubleshooting guide with Git Bash guidance
- Windows uses Git Bash for cross-platform bash script compatibility

.github/workflows/tinytorch-validate-dev.yml

@@ -29,9 +29,9 @@ name: 🔥 TinyTorch Validate (Dev)
 #   - Called by publish: all (pre-release gate)
 #
 # OS Support:
-#   - Default: Linux only (ubuntu-latest)
+#   - Default: Both Linux and Windows (ubuntu-latest, windows-latest)
 #   - Manual trigger can select: linux, windows, or all
-#   - Windows support is experimental - use to identify compatibility issues
+#   - Windows uses Git Bash (shell: bash) for cross-platform compatibility
 #
 # =============================================================================
 
@@ -134,15 +134,14 @@ jobs:
 
           echo "test_type=$TEST_TYPE" >> $GITHUB_OUTPUT
 
-          # Determine OS matrix based on input (default: linux only)
-          # Manual dispatch can select windows or all for experimental testing
+          # Determine OS matrix based on input (default: both Linux and Windows)
           if [ "${{ github.event_name }}" = "workflow_call" ]; then
             OS_INPUT="${{ inputs.os }}"
           elif [ "${{ github.event_name }}" = "workflow_dispatch" ]; then
             OS_INPUT="${{ github.event.inputs.os }}"
           else
-            # Automatic triggers always use Linux only
-            OS_INPUT="linux"
+            # Automatic triggers run both Linux and Windows
+            OS_INPUT="all"
           fi
 
           case "$OS_INPUT" in