fix(core): ensure migration framework records schema version automatically

The migration runner now inserts (OR REPLACE) the schema_version row
after each successful migration batch, regardless of whether the
migration SQL itself contains a self-registering INSERT. This prevents
version tracking gaps when a .sql migration omits the bookkeeping
statement, which would leave the schema at an unrecorded version and
cause re-execution attempts on next startup.

Legacy migrations that already self-register are unaffected thanks to
the OR REPLACE conflict resolution.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/core/db.rs

@@ -143,6 +143,20 @@ pub fn run_migrations(conn: &Connection) -> Result<()> {
 
         match conn.execute_batch(sql) {
             Ok(()) => {
+                // Framework-managed version bookkeeping: ensures the version is
+                // always recorded even if a migration .sql omits the INSERT.
+                // Uses OR REPLACE so legacy migrations that self-register are harmless.
+                conn.execute(
+                    "INSERT OR REPLACE INTO schema_version (version, applied_at, description) \
+                     VALUES (?1, strftime('%s', 'now') * 1000, ?2)",
+                    rusqlite::params![version, version_str],
+                )
+                .map_err(|e| LoreError::MigrationFailed {
+                    version,
+                    message: format!("Failed to record schema version: {e}"),
+                    source: Some(e),
+                })?;
+
                 conn.execute_batch(&format!("RELEASE {}", savepoint_name))
                     .map_err(|e| LoreError::MigrationFailed {
                         version,