v0.1.0 release candidate

[Shakargy]

v0.1.0 release candidate

Prepares the final v0.1.0 release while the repo stays private. No product behavior changes.

What changed

• README ## Demo — embedded the approved thumbnail linking to the public YouTube demo (https://youtu.be/1Hiu3Y9J_SI).
• assets/devtime-demo-thumbnail-v0.1.0.png — added the approved 1920×1080 thumbnail.
• Version bump 0.0.7 → 0.1.0 — pyproject.toml + src/devtime/__init__.py; dtc version and package metadata both report 0.1.0. Updated the version test accordingly.
• RELEASE_NOTES_v0.1.0.md — finalized (renamed from the draft), honest, with the live demo link.
• GITHUB_RELEASE_PREP.md — demo link, thumbnail path, version decision (0.1.0), final release-notes path, gate updated, and the clean-clone test record.
• LAUNCH_POSTS.md — added the YouTube link; GitHub URL marked "use only after the repo is public".
• Minor doc-version reconciliation in QUICKSTART/DEMO_SCRIPT (current behavior now labeled v0.1.0).

Clean-clone test (private clone, RC branch)

Windows 11 / Python 3.11.9 / pip install -e ".[dev]" → 88 passed, version 0.1.0, demo smoke (init/scan/concepts/explain "Billing Webhooks") produced the documented output (Score 58/100, missing-decision uncertainty). No issues.

Confirmations

• No product behavior changes (no concept/risk/scanner logic changes).
• Repo remains private; visibility unchanged.
• v0.1.0 not tagged. Visibility flip and tag are the explicit final manual steps.

Do not merge or tag automatically — waiting for approval.