Document E2E testing in CLAUDE.md, README.md, and Makefile

Add E2E test requirement to critical rules, document the test in both
CLAUDE.md and README.md development sections, and add a `make e2e`
target. Fix help grep pattern to include digits so `e2e` appears.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: ret2libc

CLAUDE.md

@@ -8,6 +8,7 @@ Pre-configured cloud-init, Tailscale VPN (enabled by default), and SSH config ma
 - **Never use `pip`** — always use `uv` for all Python operations
 - **Always run `prek run`** before committing (or `prek install` to auto-run on commit)
 - **Keep README.md in sync** when adding commands or features
+- **Run E2E tests before pushing** changes that affect core workflows (create, destroy, SSH config, cloud-init, Tailscale)
 
 ## Quick Commands
 
@@ -35,6 +36,8 @@ dropkit/
 │   └── templates/
 │       └── default-cloud-init.yaml
 └── tests/
+    ├── e2e/
+    │   └── test_lifecycle.sh      # Full create → SSH → destroy E2E test
     ├── test_api.py
     ├── test_config.py
     ├── test_main_helpers.py
@@ -151,6 +154,20 @@ uv run pytest -k "validate_ssh"            # Pattern match
 uv run pytest -v                           # Verbose
 ```
 
+### E2E Testing
+
+The E2E lifecycle test creates a real droplet, verifies SSH connectivity,
+and destroys it. **Run before pushing changes that affect core workflows**
+(create, destroy, SSH config, cloud-init, Tailscale).
+
+```bash
+./tests/e2e/test_lifecycle.sh
+```
+
+Requires a valid dropkit config (`~/.config/dropkit/config.yaml`).
+Optional environment variables: `DROPLET_NAME`, `DROPLET_REGION`,
+`DROPLET_SIZE`, `DROPLET_IMAGE`, `E2E_SSH_TIMEOUT`.
+
 ## Pydantic Models
 
 - **`DropkitConfig`** — Root config with `extra='forbid'`

Makefile

@@ -1,7 +1,7 @@
-.PHONY: help dev lint format test audit
+.PHONY: help dev lint format test e2e audit
 
 help: ## Show available targets
-	@grep -E '^[a-zA-Z_-]+:.*##' $(MAKEFILE_LIST) | awk -F ':.*## ' '{printf "  %-12s %s\n", $$1, $$2}'
+	@grep -E '^[a-zA-Z0-9_-]+:.*##' $(MAKEFILE_LIST) | awk -F ':.*## ' '{printf "  %-12s %s\n", $$1, $$2}'
 
 dev: ## Install all dependencies
 	uv sync --all-groups
@@ -15,5 +15,8 @@ format: ## Auto-format code
 test: ## Run tests
 	uv run pytest
 
+e2e: ## Run E2E lifecycle test (creates a real droplet)
+	./tests/e2e/test_lifecycle.sh
+
 audit: ## Audit dependencies for vulnerabilities
 	uv run pip-audit

README.md

@@ -217,6 +217,29 @@ The droplet might belong to someone else. List your droplets:
 dropkit list
 ```
 
+## Development
+
+### Running Unit Tests
+
+```bash
+uv run pytest                # All tests
+uv run pytest -v             # Verbose output
+uv run pytest -k "pattern"   # Filter by name
+```
+
+### Running E2E Tests
+
+The E2E lifecycle test creates a real droplet, verifies SSH connectivity,
+and destroys it. Run before pushing changes that affect core workflows.
+
+```bash
+./tests/e2e/test_lifecycle.sh
+```
+
+Requires a valid dropkit config (`~/.config/dropkit/config.yaml`).
+Optional environment variables: `DROPLET_NAME`, `DROPLET_REGION`,
+`DROPLET_SIZE`, `DROPLET_IMAGE`, `E2E_SSH_TIMEOUT`.
+
 ## Technology Stack
 
 - **CLI Framework**: [Typer](https://typer.tiangolo.com/) - Modern CLI framework