Hex editor, terminal text selection, F3 size calc, F3/F4 consolidation

[bluestreak01]

Summary

• Hex editor: full editing for binary files — cursor, hex/ASCII editing, undo/redo, pattern search, goto offset, selection with data inspector, unsaved changes prompt
• F4 auto-detects file type: text → editor, binary → hex editor, parquet → parquet viewer. F3 repurposed.
• F3 directory size calculation: async recursive scan with live progress spinner, works on selections, parallel dir scanning
• Terminal text selection: click-drag, double/triple-click in shell and Claude panels. Ctrl+C copies selection (SIGINT when no selection)
• Zero-allocation hex render loop with compile-time lookup tables
• 545 total tests passing, zero clippy warnings

Hex Editor

• Modifications stored as in-place overlay (HashMap) — only changed bytes in memory
• Save writes only modified bytes with sorted sequential I/O
• Search scans file in 1MB chunks with overlap for boundary-spanning patterns
• Data inspector: select 1/2/4/8 bytes to see u/i/float values in both endiannesses
• Cursor tracking between hex and ASCII panes
• Uses shared search dialog (F7) and goto dialog (g) consistent with text editor

F3 Size Calculation

• F3 on directory: async background thread walks recursively, spinner in size column, actual size when done
• F3 on multi-selection: all dirs scanned in parallel, files summed immediately
• F3 again on calculated dir: re-scans (force refresh)
• Sizes persist until panel reload

Test plan

• cargo test — 545 tests pass
• cargo clippy — zero warnings
• cargo fmt --check — clean
• F4 on binary → hex editor, text → editor, parquet → parquet viewer
• Hex: edit nibbles, Tab for ASCII, Ctrl+S save, Ctrl+Z undo, F7 search, g goto
• Hex: Shift+arrows select, status bar shows numeric values for 1/2/4/8 byte selections
• F3 on directory shows spinner then size
• F3 on multi-selection calculates all in parallel
• Shell/Claude: drag select text, Ctrl+C copies selection

🤖 Generated with Claude Code