Document and record the real v0.2 workflow

[SmartAI]

Summary

• audit every README section against the v0.2.0 CLI and tighten install, preparation, recovery, offline, and skill-install guidance
• replace the synthetic v0.1 lifecycle GIF with an eight-frame recording rendered from a real published-wheel session in a fresh Herdr workspace
• include the exact accessible terminal transcript and preserve it in future source distributions

The recorded session creates feature/demo, writes and runs demo.py, commits it, runs wtg done, lists the available slot, and reacquires that exact slot as feature/reused (reused: True).

Validation

• python3 -m unittest discover -v — 91 passed, 1 skipped
• WTG_TEST_ARTIFACTS=1 python3 -m unittest -v tests.test_artifacts — passed
• python3 -m build && python3 -m twine check dist/* — passed
• release wheel download, Linux/macOS checksum commands, isolated uv tool install, and wtg version — passed
• GIF validation — 960×540, 8 frames, 17.3 seconds
• python3 -m compileall -q src tests
• git diff --check