implement Trie-based local autocomplete for commit messages

Proposal

Implement a local, high-performance autocomplete (typeahead) mechanism for commit message generation using a Trie data structure.

Context

Instead of relying on real-time LLM API calls, which introduce latency and performance overhead in the TUI, a local Trie-based approach could provide instant suggestions for common commit message verbs, scopes, or frequently used phrases.

Implementation Ideas

• Non-blocking: The autocomplete should be local and instantaneous to ensure the TUI remains responsive.
• Trigger: Rather than live-as-you-type, it could be triggered via a specific keystroke (e.g., TAB or CTRL-SPACE) to suggest completions.
• Data Source: The Trie could be populated with common conventional commit structures, previous commit messages, or a project-specific word list.

This approach avoids the complexity and UX pitfalls of live LLM typeahead while still providing productivity gains.

Start by locating the TUI's commit message generation and input-handling entry points. Decide how the Trie is populated and which completion trigger and suggestion behavior the project should support. Done means local, non-blocking suggestions for commit messages without relying on real-time LLM API calls.