Revert "Merge pull request #3087 from deepseek-harness/worktree/remove-ignorable-session-events"

This reverts commit 2123b2f418b1c8fbb86dc327b598fb11423da226, reversing
changes made to 3c0b5c68ce697537a21084f9135663017474a2e1.

packages/session/session-persistence-sqlite/resources/sql/schema.sql

@@ -26,6 +26,6 @@ CREATE TABLE events (
   data              ANY NOT NULL,
   source_event_seqs ANY,
   surface_op        TEXT,
-  is_packed         INTEGER NOT NULL CHECK (is_packed IN (0, 1)),
+  ignorable         INTEGER CHECK (ignorable IS NULL OR ignorable IN (0, 1)),
   PRIMARY KEY (session_id, seq)
 ) STRICT;