refactor: reorganize into monorepo with separate subprojects

Structure webber into three independent subprojects:
- webber-api/: FastAPI backend server with all agent code
- webber-cli/: Standalone CLI client (renamed from cli/ to webber_cli/)
- webber-sandbox/: Test project for functional testing

Key changes:
- Each subproject has its own .venv (Python 3.12+)
- Added sandbox.sh for managing test project templates
- Created sandbox-templates/ with calculator-cli and empty starter
- Updated CI/CD for prefixed tags (api/v*, cli/v*)
- Added comprehensive AGENTS.md with operational instructions
- Added gitignore filtering to glob and grep tools
- Created pyproject.toml for each subproject

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

webber-api/pyproject.toml

@@ -0,0 +1,69 @@
+[project]
+name = "webber-api"
+version = "0.3.0"
+description = "Webber API - Multi-Agent AI Development Server"
+authors = [
+    {name = "jpmschweitzer"}
+]
+readme = "README.md"
+requires-python = ">=3.12"
+license = {text = "MIT"}
+classifiers = [
+    "Development Status :: 3 - Alpha",
+    "Framework :: FastAPI",
+    "Programming Language :: Python :: 3.12",
+    "Topic :: Software Development :: Code Generators",
+]
+
+[build-system]
+requires = ["setuptools>=75.0", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+where = ["."]
+include = ["src*"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+python_files = ["test_*.py"]
+python_functions = ["test_*"]
+addopts = "-v"
+
+[tool.mypy]
+python_version = "3.12"
+warn_return_any = true
+warn_unused_ignores = true
+strict = false
+ignore_missing_imports = true
+
+[tool.ruff]
+target-version = "py312"
+line-length = 100
+src = ["src", "tests"]
+
+[tool.ruff.lint]
+select = [
+    "E",      # pycodestyle errors
+    "W",      # pycodestyle warnings
+    "F",      # Pyflakes
+    "I",      # isort
+    "B",      # flake8-bugbear
+    "C4",     # flake8-comprehensions
+    "UP",     # pyupgrade
+    "SIM",    # flake8-simplify
+    "TCH",    # flake8-type-checking
+    "RUF",    # Ruff-specific rules
+]
+ignore = [
+    "E501",   # line too long (handled by formatter)
+    "B008",   # function call in default argument (FastAPI Depends)
+    "B904",   # raise without from (sometimes intentional)
+]
+
+[tool.ruff.lint.isort]
+known-first-party = ["src"]
+
+[tool.ruff.format]
+quote-style = "double"
+indent-style = "space"
+skip-magic-trailing-comma = false