fix: scope PYTHONDONTWRITEBYTECODE to test targets only

Addresses review feedback to prevent unintended side effects from
global PYTHONDONTWRITEBYTECODE export.

**Problem:**
With .EXPORT_ALL_VARIABLES enabled, setting PYTHONDONTWRITEBYTECODE=1
globally affected ALL make targets (dev servers, docker builds, docs),
which could:
- Slow down dev servers by preventing .pyc caching
- Affect docker builds that benefit from .pyc files
- Impact other tooling unnecessarily

**Solution:**
- Removed global PYTHONDONTWRITEBYTECODE variable from Makefile
- Set PYTHONDONTWRITEBYTECODE=1 inline for test-related targets only
- Removed from .env.example (no longer needed)
- Kept in CI workflows (appropriate for CI environment)
- Added comment explaining the scoping decision

**Affected targets:**
- test: PYTHONDONTWRITEBYTECODE=1 pytest
- coverage: PYTHONDONTWRITEBYTECODE=1 pytest + coverage

**Unaffected targets (benefit from .pyc caching):**
- run-dev-server, run-dev-bot (faster restarts)
- docker-* (faster container startup)
- docs-* (faster builds)
- install, type-check, lint (faster execution)

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

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

Author: JacobCoffee

.env.example

@@ -13,7 +13,6 @@ WEB_URL=https://byte-bot.app
 SECRET_KEY=ThisIsNotAProductionToken
 ENVIRONMENT=dev
 DEBUG=True
-PYTHONDONTWRITEBYTECODE=1
 
 # --- Database Settings
 # Prefix is ``DB_`` for all Database settings

Makefile

@@ -9,7 +9,6 @@ USING_UV		=	$(shell grep "tool.uv" pyproject.toml && echo "yes")
 VENV_EXISTS		=	$(shell python3 -c "if __import__('pathlib').Path('.venv/bin/activate').exists(): print('yes')")
 UV_OPTS 		?=
 UV 			    ?= 	uv $(UV_OPTS)
-PYTHONDONTWRITEBYTECODE = 1
 
 .EXPORT_ALL_VARIABLES:
 
@@ -118,12 +117,15 @@ ruff-noqa: ## Runs Ruff, adding noqa comments to disable warnings
 type-check: ## Run ty type checker
 	@$(UV) run --no-sync ty check
 
+# PYTHONDONTWRITEBYTECODE is set inline for test targets to prevent .pyc generation
+# during testing, which reduces I/O overhead. It's NOT set globally to avoid affecting
+# dev servers, docker builds, and other targets that benefit from .pyc caching.
 test:  ## Run the tests
-	@$(UV) run --no-sync pytest
+	@PYTHONDONTWRITEBYTECODE=1 $(UV) run --no-sync pytest
 
 coverage:  ## Run the tests and generate coverage report
-	@$(UV) run --no-sync pytest --cov=byte_bot
-	@$(UV) run --no-sync coverage html
+	@PYTHONDONTWRITEBYTECODE=1 $(UV) run --no-sync pytest --cov=byte_bot
+	@PYTHONDONTWRITEBYTECODE=1 $(UV) run --no-sync coverage html
 	@$(UV) run --no-sync coverage xml
 
 check-all: lint type-check fmt test  ## Run all linting, formatting, and tests

tests/README.md

@@ -204,9 +204,10 @@ Current test execution time (1036 tests total):
 Following best practices from [awesome-pytest-speedup](https://github.com/zupo/awesome-pytest-speedup), we've implemented several optimizations:
 
 #### 1. PYTHONDONTWRITEBYTECODE=1
-- **Impact**: Reduces I/O overhead
-- **Location**: `Makefile`, `.github/workflows/ci.yml`, `.env.example`
-- Prevents `.pyc` file generation during test runs
+- **Impact**: Reduces I/O overhead during test runs
+- **Location**: Scoped to test targets in `Makefile`, set globally in `.github/workflows/ci.yml`
+- Prevents `.pyc` file generation during testing
+- **Note**: NOT set globally to avoid affecting dev servers, Docker builds, and other targets that benefit from .pyc caching
 
 #### 2. Disabled Unnecessary Builtin Plugins
 - **Impact**: Faster collection