Adds an AGENTS.md rule under the pre-push gate naming the gated surface
(first-party source) and everything excluded from it (each client's build/,
web's dist/ and storybook-static/, coverage/, test-servers/build,
core/**/{build,dist}, *.tsbuildinfo), why gating generated output is harmful
even when it only warns, and the fact that the three coverage guards assert
the converse and so cannot catch this drift. Mirrored into
.github/copilot-instructions.md per the maintenance rules.
Signed-off-by: cliffhall <cliff@futurescale.com>
4fd7f39acf