feat: add apps extension pack

[keys-i]

Part of #23.

Depends on keys-i/tools#8 and #30.

Summary

Add the typed dashboard contract for the native apps workbench and document a local timer example. Fix apply/direct routing so only selected choice values and active flags control execution; hostile free-text collisions no longer change the workflow.

Scope

• bin/
• dev/
• lib/
• sys/
• Documentation or repository settings

Testing

Commands run:

bash -n run.sh
bash run.sh --self-test
uv run dev/gui.py --self-test
git diff --check

Tested systems and interpreter versions:

macOS 26.5.2; Python 3.14 through the pinned uv environment

Checklist

• The change is focused and contains no unrelated files.
• The code is clean and comments explain intent or risk.
• New or changed behaviour has a repeatable test or documented manual check.
• Help text and dependencies are current.
• Destructive behaviour and elevated permissions are clearly disclosed.
• No credentials, private data, or machine-specific paths are included.

Reviewer Notes

The pack launches keys-tools' apps executable; it does not download or publish the package. Interactive mode is shown as a direct-terminal command. Roll back commit b7d6906 to remove the pack and routing fix.