Add TinySpec extension to community catalog (#2147)

* Add TinySpec extension to community catalog

- 3 commands: tinyspec, implement, classify for lightweight single-file workflow
- 1 hook: before_specify for auto-classifying task complexity
- Addresses community request in issue #1174 (22+ reactions)

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

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Co-authored-by: Manfred Riem <15701806+mnriem@users.noreply.github.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>