Implement binary SAVE/LOAD, INKEY$ extended keys, golden tests, update to v0.10.0

Binary SAVE/LOAD: SAVE now writes tokenized binary by default (0xFF header
format), matching original GW-BASIC behavior. SAVE "file",A for ASCII.
LOAD auto-detects binary vs ASCII from the first byte. Command-line file
loading also auto-detects, so binary .BAS files just work.

INKEY$ extended keys: arrow keys, Home/End/PgUp/PgDn, Insert/Delete, and
F1-F10 now return the correct CHR$(0) + scan_code two-byte sequences per
the IBM PC convention. Refactored event trap key parsing to use tui_read_key()
instead of duplicating escape sequence parsing.

Golden-file regression tests: generated .expected output files for 55 of 58
test programs (3 timing-dependent tests excluded). The test runner now
reports compat match status alongside pass/fail.

Classic programs: added Hamurabi, Lunar Lander, Gunner, and Diamond from
David Ahl's BASIC Computer Games (1978) in tests/classic/ for manual
compatibility testing.

Docs updated with compiler roadmap item and hardware I/O simulator plan.

tests/programs/inkey_ext.bas

@@ -0,0 +1,5 @@
+10 REM Test INKEY$ extended key support (non-interactive)
+20 REM When no key is available, INKEY$ returns ""
+30 K$ = INKEY$
+40 IF LEN(K$) = 0 THEN PRINT "Empty INKEY$ ok" ELSE PRINT "FAIL: expected empty"
+50 PRINT "INKEY$ extended keys test passed"

tests/programs/save_binary.bas

@@ -0,0 +1,9 @@
+10 REM Binary SAVE/LOAD round-trip test
+20 REM Create a test program, save as binary default, load binary back
+30 OPEN "gwbasic_binsrc.bas" FOR OUTPUT AS #1
+40 PRINT #1, "10 PRINT "+CHR$(34)+"Binary round-trip ok"+CHR$(34)
+50 PRINT #1, "20 SAVE "+CHR$(34)+"gwbasic_roundtrip.bas"+CHR$(34)
+60 PRINT #1, "30 KILL "+CHR$(34)+"gwbasic_binsrc.bas"+CHR$(34)
+70 PRINT #1, "40 KILL "+CHR$(34)+"gwbasic_roundtrip.bas"+CHR$(34)
+80 CLOSE #1
+90 LOAD "gwbasic_binsrc.bas",R