Codemm v1.0.0-beta.6

Unsigned beta installers for macOS and Windows. Each needs one Open Anyway step (docs/desktop/beta-plan.md).

• You're never stuck behind an activity. When an activity can't be written yet, Come back later moves you on: the topics after it unlock once you've read its lesson. The skipped topic still waits for you, and its own activity is the only one a skip lets you pass.
• Activities fit the lesson. Your agent now gets the lesson's text and your last result, and writes an activity for that concept at a stated difficulty. A Spring Boot topic gets a Spring Boot activity, not a plain Java one, and setup or configuration topics can get setup activities.
• Frameworks set up more reliably. A setup that fails its checks continues the agent's own session, so it fixes what it proposed instead of starting over. A failing build shows that step's own output, a slow download is no longer blamed on the track, and tracks are told how to cache their dependencies.
• Activity writing tries a different way. When three tries fail, the agent goes on in the same session, told to change its approach instead of repeating it. Reference solutions get twice the track's own time, and a test runner that reports nothing says what to check.
• Codex recommends gpt-6-luna, which sets up the larger frameworks the smaller model couldn't.
• Technical docs. docs/architecture.md explains Codemm's architecture and data model with diagrams: an ERD, use cases, classes, sequences and the components.