Fix task auto-commit with pre-commit hook

Implemented proper pre-commit hook that: - Calls 'task export --flush'
to consolidate tasks - Auto-stages .tasks/tasks.jsonl if modified -
Runs before every commit

Added reminder message after 'task update' to inform users that task
changes will be committed on next git commit.

Updated AGENTS.md to document the auto-commit behavior.

This fixes the bug where task status updates (e.g., marking tasks as
Done) were not being committed to git.

1 files changed, 2 insertions, 0 deletions

diff --git a/AGENTS.md b/AGENTS.md
index 3cd9aa7..c07d8ed 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -88,6 +88,8 @@ task update t-20241108120000 in-progress
 task update t-20241108120000 done
 ```
 
+**Note**: Task updates modify `.tasks/tasks.jsonl` but don't auto-commit. The pre-commit hook will automatically export and stage task changes on your next `git commit`.
+
 ### View Dependencies
 ```bash
 task deps <id>