ci: tighten pre-commit guardrails (#3346)

* ci: tighten pre-commit guardrails

Signed-off-by: Georg Heiler <georg.kf.heiler@gmail.com>

* ci: validate pre-commit guardrail changes

Signed-off-by: Georg Heiler <georg.kf.heiler@gmail.com>

* ci: switch hook validation to prek

Signed-off-by: Georg Heiler <georg.kf.heiler@gmail.com>

* ci: exempt active slim plan from max-lines

Signed-off-by: Georg Heiler <georg.kf.heiler@gmail.com>

* ci: move max-lines config under github

Signed-off-by: Georg Heiler <georg.kf.heiler@gmail.com>

* ci: fail on uncovered tach modules

Signed-off-by: Georg Heiler <georg.kf.heiler@gmail.com>

* ci: ignore generated docs in max-lines check

Signed-off-by: Georg Heiler <georg.kf.heiler@gmail.com>

* ci: clarify local validation tasks

Signed-off-by: Georg Heiler <georg.kf.heiler@gmail.com>

* docs: refine agent instructions

Signed-off-by: Georg Heiler <georg.kf.heiler@gmail.com>

* ci: replace mypy with ty

(cherry picked from commit 382afbde8f00abfaeba95ea9c8e9cc603f27a2d9)
Signed-off-by: Georg Heiler <georg.kf.heiler@gmail.com>

* ci: replace justfile with makefile

Signed-off-by: Georg Heiler <georg.kf.heiler@gmail.com>

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Signed-off-by: Georg Heiler <georg.kf.heiler@gmail.com>