List and edit in-memory sounds in soundbanks

docs/reverse-engineering/findings.md

@@ -72,6 +72,19 @@ Conclusion: approach A works end-to-end in-game. Use >= 30 s probes for the intr
     UI, grunts) are in-memory WEMs inside soundbanks: 65 loose `SFX\*.bnk` (1,117) and 3,340 banks embedded in
     the `.upk` packages (15,641; many banks copied into several packages). None are in the catalog; the WAD
     side is complete. Inventory, layout and editing consequences: `docs/formats/banks.md`.
+17. (2026-10-09) Speech lines have **per-language media IDs**: every package carries one BKPK table per language
+    for the same WAD entry. 396 lines (78-80 per language) have a prefetch head (first N bytes) in banks; each
+    head equals the start of exactly one language's WEM.
+18. (2026-10-09) In-game test of in-memory sounds (`ackit verify --ingame --banks`): 77 probes written into the
+    78 sounds stored in the Frontend*/Startup packages (54 files: patched LZO packages + loose banks). The game
+    starts and runs, all 68 probe byte patterns are found in its memory (it loaded the patched packages), revert
+    byte-identical: PASS. Not shown: a probe being *heard*. Only 7 Vorbis streams start on the title screen
+    (setups 4f708975, 6ded1c65, 92f94a3f, d93b5944, d4b2e824: shared by hundreds of sounds, music included) and
+    none is a probe. Tried: Enter/arrow keys posted to the game window (`debugger.post_key`, WM_KEYDOWN) to reach
+    the main menu: no UI sound followed (the game probably reads input another way; global SendInput is not
+    used on purpose); a breakpoint on the setup parser entry: no extra events. Hypotheses: no in-memory sound
+    plays without input; the decode path is the same as for WAD sounds (same WEM rules, 300/300 in-memory WEMs
+    rebuild byte-identically), so playback is expected to work like E4/E10.
 
 ## Old path -> new path
 `scripts/harness.py` -> `ackit verify --ingame` (ackit/verify/ingame.py); `scripts/validate_builder.py` ->