chore(githooks): remove pre-push hook (#22956)

## Summary
- remove the `pre-push` git hook script from the repository
- remove the `make pre-push` target and related Makefile documentation
- update contributor and agent docs so they only describe the remaining
`pre-commit` hook

## Validation
- `make pre-commit`
- `git diff --check`

---
_Generated with [`mux`](https://github.com/coder/mux) • Model:
`openai:gpt-5.4` • Thinking: `high`_

scripts/githooks/pre-commit

@@ -3,7 +3,6 @@
 # Pre-commit hook that runs CI-equivalent checks locally.
 # Runs `make pre-commit` (gen, fmt, lint, typos, build) which
 # catches most CI failures without needing Docker or Playwright.
-# The full CI suite (including tests) runs via the pre-push hook.
 #
 # Installation (worktree-compatible):
 #

scripts/githooks/pre-push

@@ -1,26 +0,0 @@
-#!/usr/bin/env bash
-#
-# Pre-push hook that runs the full CI suite locally.
-# Runs `make pre-push` (gen, fmt, lint, typos, build, tests)
-# to catch issues before they reach CI.
-#
-# The pre-commit hook already runs the lite checks on each commit.
-# This hook adds the heavier checks (test-postgres, test-js,
-# test-e2e, sqlc-vet, offlinedocs) before pushing.
-#
-# Installation (worktree-compatible):
-#
-#   git config core.hooksPath scripts/githooks
-#
-# Bypass: git push --no-verify
-
-set -euo pipefail
-
-cd "$(git rev-parse --show-toplevel)"
-unset GIT_DIR
-
-# In linked worktrees, set worktree-scoped hooksPath to override shared config.
-if [[ "$(git rev-parse --git-dir)" != "$(git rev-parse --git-common-dir)" ]]; then
-	git config --worktree core.hooksPath scripts/githooks
-fi
-exec make pre-push