refactor: comprehensive code review fixes across core and programmer crates

[ArthurHeymans]

Fix critical bugs, reduce code duplication, and improve Rust idioms
based on a full code review of the codebase.

Critical fixes:

• operations::write() now respects max_write_len() to prevent data corruption
• Guard integer underflow in smart_write_region when data is empty
• Log data loss risk when erase+restore fails during region writes
• Handle erase blocks extending both before AND after a write region

High priority:

• Add multi-I/O read support (dual/quad) to SpiFlashDevice::read()
• Add Box blanket impl for trait object usage
• Extract default_execute/default_execute_with_vec helpers to deduplicate
  SpiMaster::execute() across 7 programmer crates

Medium priority:

• Add addr context to ReadError, WriteError, VerifyError variants
• Replace process::exit(1) with proper error returns in CLI commands
• Add descriptive messages to assert_eq! in operations.rs
• Log warnings instead of silently discarding exit_4byte_mode errors
• Deduplicate FlashContext methods across cfg blocks
• Standardize LayoutError::IoError to use Display formatting consistently

Low priority:

• Name magic timing constants in spi25.rs (WRSR_POLL_US, etc.)
• Add WpError: std::error::Error and Display for LayoutSource
• Use VecDeque instead of Vec for WASM StatusLog (O(1) vs O(n) removal)
• Use strip_prefix in parse_number
• Extract shared format_size utility for human-readable byte formatting
• Add aliases field to ProgrammerInfo
• LayoutError::IoError now carries inner error string