chore: ignore generated WHP16 module binaries

[sit-d]

Summary

• Add a root .gitignore for WHP16 module artifacts generated by fasm2.cmd / Session -> Build.
• Keep source/include/docs files trackable while ignoring local x16/*.bin outputs and common assembler listing/symbol sidecars.
• Add common OS noise patterns so local desktop files do not appear as repository changes.

Verification

• Ad-hoc verification: ran /tmp/hermes-verify-f3sfztek.py to assert generated artifact patterns are ignored, source/docs/build entrypoints remain trackable, and whitespace checks pass. The verifier exited 0 and was removed afterward.
• The verifier checked git check-ignore --no-index -v x16/my_first.bin x16/test_console_tx.bin x16/test_console_tx.lst x16/test_console_tx.map x16/test_console_tx.sym x16/test_console_tx.fas.
• The verifier checked that git check-ignore --no-index -v x16/template.asm x16/module_impl.inc fasm2.cmd readme.md returns status 1 as expected.
• The verifier ran git diff --check.

Notes / Limitations

• This is repository hygiene only; I did not run the Windows WHP16 executable or assemble modules in the Linux cron environment.