catini: fix file truncation by replacing FileReadLine with FileRead-based line assembly

[Copilot]

catini was silently truncating INI files mid-read on the STM32 target because the embedded FS's FileReadLine (fgets-like) returns NULL prematurely. cat uses FileRead (fread-like) and displays files correctly.

Changes

• commands/catini/catini.c
  • Replace Dmod_FileReadLine loop with a Dmod_FileRead chunk-loop that manually assembles lines, adding a second heap-allocated read buffer (256 B) — mirrors the proven pattern in cat.c
  • Skip \r characters to correctly handle \r\n line endings
  • Pass lines to print_highlighted_line without trailing \n; every branch now appends \n after VT100_RESET, so the reset escape always precedes the newline instead of appearing at the start of the next line

Before (buggy):  "PI1\n\033[0m"          → \033[0m at start of next line
After  (fixed):  "PI1\033[0m\n"          → \033[0m before newline, every line type