fix(sync-check): ignore generated python and elisp artifacts

Pre-commit caught a false-positive on its first real-world run. The
.ai/scripts/__pycache__ directory created by make test (pytest writes
.pyc and .pytest_cache, emacs writes .elc) was flagged as drift
against the canonical's clean tree.

Added matching --exclude patterns to the diff -rq check and the --fix
rsync calls. Patterns: __pycache__, *.pyc, *.pyo, .pytest_cache, *.elc.
The --fix excludes prevent rsync's --delete from wiping the mirror's
__pycache__ when the canonical has none.

Four new bats tests cover the exclusions. All 12 pass.

1 files changed, 30 insertions, 0 deletions

diff --git a/scripts/tests/sync-check.bats b/scripts/tests/sync-check.bats
index df775b3..17c9189 100644
--- a/scripts/tests/sync-check.bats
+++ b/scripts/tests/sync-check.bats
@@ -84,3 +84,33 @@ setup() {
     [ "$status" -eq 2 ]
     [[ "$output" == *"not inside a git checkout"* ]]
 }
+
+@test "generated Python artifacts in mirror don't count as drift" {
+    mkdir -p .ai/scripts/__pycache__
+    touch .ai/scripts/__pycache__/foo.cpython-314.pyc
+    touch .ai/scripts/some.pyc
+    run scripts/sync-check.sh
+    [ "$status" -eq 0 ]
+}
+
+@test "compiled elisp artifacts in mirror don't count as drift" {
+    touch .ai/scripts/foo.elc
+    run scripts/sync-check.sh
+    [ "$status" -eq 0 ]
+}
+
+@test "pytest cache in mirror doesn't count as drift" {
+    mkdir -p .ai/scripts/.pytest_cache
+    touch .ai/scripts/.pytest_cache/CACHEDIR.TAG
+    run scripts/sync-check.sh
+    [ "$status" -eq 0 ]
+}
+
+@test "--fix preserves generated artifacts in mirror" {
+    mkdir -p .ai/scripts/__pycache__
+    touch .ai/scripts/__pycache__/foo.cpython-314.pyc
+    echo "drift" > .ai/protocols.org
+    run scripts/sync-check.sh --fix
+    [ "$status" -eq 0 ]
+    [ -f .ai/scripts/__pycache__/foo.cpython-314.pyc ]
+}