TimerMeet Python Builder

Overview

Implement features and fixes in TimerMeet's Python desktop app without regressing alarm reliability -- the entire reason this app exists is that its PHP/JS predecessor's reminders depended on a browser tab staying open.

Workflow

1. Read SDD.md before changing behavior that affects product scope or validation (or hand off to the timermeet-spec-driver skill first).
2. Identify the right module (see references/module-map.md) and implement the smallest change that satisfies the request, reusing existing helpers rather than re-deriving logic.
3. Run the verification commands (see references/validation.md) before finishing.
4. Use the timermeet-code-commenter skill on any new non-obvious logic.
5. Bump timermeet_app/__init__.py::__version__ when user-visible behavior changes, and update README.md/SDD.md to match.
6. If the change should ship as a compiled binary, use the timermeet-exe-packager skill to rebuild TimerMeet.exe.

Hard constraints

• No network listener, HTTP server, or browser dependency -- ever.
• No eval/exec/pickle, no shell-string subprocess/os.system.
• Every URL-opening path goes through timermeet_app.security.is_http_url().
• Every disk write goes through timermeet_app.security.atomic_write_text() (directly or via storage.py).
• Keep the Tkinter main thread non-blocking -- background threads or root.after(), never a blocking sleep on the UI thread.
• Comment only code that would otherwise be hard to parse quickly; don't over-engineer beyond the request.

References

• references/module-map.md -- what lives in each timermeet_app/*.py file.
• references/validation.md -- the exact commands to run before calling a change done.