Add bats test suite for git-manager and obsidian-vault-kb

Isolated per-test $HOME sandboxing via tests/helpers/common.bash.
Covers both plugins' wrapper scripts, their setup.sh, and
git-manager's two PreToolUse hooks (53 tests). Verified the suite
catches regressions by temporarily reintroducing the recently-fixed
vault_search.sh -g/-- ordering bug and confirming it fails.

tests/obsidian-vault-kb/vault_index.bats

@@ -0,0 +1,47 @@
+#!/usr/bin/env bats
+# Tests for skills/obsidian-vault-kb/scripts/vault_index.sh.
+
+load '../helpers/common'
+
+setup() {
+  sandbox_home
+  SCRIPT="$REPO_ROOT/skills/obsidian-vault-kb/scripts/vault_index.sh"
+  CONFIG_FILE="$HOME/.agent-skills/obsidian-vault-kb/config.json"
+  VAULT="$BATS_TEST_TMPDIR/vault"
+  make_test_vault "$VAULT"
+  write_vault_config "$CONFIG_FILE" "append" "v=$VAULT"
+}
+
+@test "folder structure excludes .obsidian and .git" {
+  run "$SCRIPT" v
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"/Notes"* ]]
+  [[ "$output" != *".obsidian"* ]]
+  [[ "$output" != *"/.git"* ]]
+}
+
+@test "note count per top-level folder counts only .md files" {
+  run "$SCRIPT" v
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"Notes: 2"* ]]
+}
+
+@test "frontmatter tags are extracted and deduplicated" {
+  run "$SCRIPT" v
+  [ "$status" -eq 0 ]
+  for tag in dns homelab networking overview; do
+    [[ "$output" == *"$tag"* ]]
+  done
+}
+
+@test "a note matching *overview* is flagged as a possible MOC file" {
+  run "$SCRIPT" v
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"homelab-overview.md"* ]]
+}
+
+@test "unknown vault name errors" {
+  run "$SCRIPT" not-a-real-vault
+  [ "$status" -eq 1 ]
+  [[ "$output" == *"no vault named"* ]]
+}