35946afc91
Refactor command system to pre-resolve cell key and grid dimensions in CmdContext, eliminating repeated GridLayout construction. Key changes: - Add cell_key, row_count, col_count to CmdContext - Replace generic CmdRegistry::register with register/register_pure/register_nullary - Cell commands (clear-cell, yank, paste) now take explicit CellKey - Update keymap dispatch to use new interactive() method - Special-case "search" buffer in SetBuffer effect - Update tests to populate new context fields This reduces code duplication and makes command execution more efficient by computing layout once at context creation time. Co-Authored-By: fiddlerwoaroof/git-smart-commit (unsloth/Qwen3.5-35B-A3B-GGUF:Q5_K_M)