Fix busy binary reinstall and add per-node log viewing.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/db/db.go

@@ -75,6 +75,7 @@ CREATE TABLE IF NOT EXISTS nodes (
     install_mode TEXT NOT NULL DEFAULT 'auto',
     last_error TEXT NOT NULL DEFAULT '',
     install_log TEXT NOT NULL DEFAULT '',
+    runtime_log TEXT NOT NULL DEFAULT '',
     agent_version TEXT NOT NULL DEFAULT '',
     last_seen_at TIMESTAMPTZ,
     created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
@@ -95,8 +96,12 @@ CREATE TABLE IF NOT EXISTS node_protocols (
 
 CREATE INDEX IF NOT EXISTS idx_node_protocols_protocol ON node_protocols(protocol_id);
 `
-	_, err := db.Exec(schema)
-	return err
+	if _, err := db.Exec(schema); err != nil {
+		return err
+	}
+	// Additive migrations for existing deployments.
+	_, _ = db.Exec(`ALTER TABLE nodes ADD COLUMN IF NOT EXISTS runtime_log TEXT NOT NULL DEFAULT ''`)
+	return nil
 }
 
 func SeedAdmin(db *sql.DB, cfg *config.Config) error {