Fix package data: Move schemas and templates into forge package

Problem: Schemas and templates were not included in installed package.
The files were in the project root but setuptools couldn't find them.

Solution:
- Move schemas/ and templates/ into forge/ package
- Update MANIFEST.in to reference forge/schemas and forge/templates
- Fix path references in cli.py (parent.parent -> parent)

This ensures schemas and templates are properly included when
the package is installed via pip/uv.

Tested:
- uv tool install from GitHub works
- workshopforge validate finds schemas ✓
- workshopforge generate finds templates ✓
- workshopforge ai check runs ✓

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

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

Author: f3rdy

MANIFEST.in

@@ -1,4 +1,4 @@
 include README.md
 include LICENSE
-recursive-include schemas *.json
-recursive-include templates *.j2 *.yml
+recursive-include forge/schemas *.json
+recursive-include forge/templates *.j2 *.yml

forge/cli.py

@@ -246,7 +246,7 @@ def validate(
     rprint(f"[blue]Validating specs in:[/blue] {spec_dir}")
 
     # Get schema directory (in package)
-    schema_dir = Path(__file__).parent.parent / "schemas"
+    schema_dir = Path(__file__).parent / "schemas"
     validator = SpecValidator(schema_dir)
 
     results = validator.validate_directory(spec_dir)
@@ -305,7 +305,7 @@ def generate(
         raise typer.Exit(1)
 
     # Generate
-    template_dir = Path(__file__).parent.parent / "templates"
+    template_dir = Path(__file__).parent / "templates"
     generator = WorkshopGenerator(loader, template_dir)
 
     try: