Tool names in builtinTools are lowercase ('grep', 'glob') but truncator
hooks were checking for capitalized names ('Grep', 'Glob'), causing
truncation to never trigger and resulting in context window overflow.
🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)
Previously, token calculation accumulated ALL assistant messages' tokens,
causing incorrect usage display (e.g., 524.9%) after compaction.
Now uses only the last message's input tokens, which reflects the actual
current context window usage.
🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)
YeonGyu-Kim