feat: read, play and emit named wavetables

[spacedevin]

Draft — needs the @spacedevin/deck release from spacedevin/deck#16, which is where wave becomes core grammar.

Deckard could not read a wave line. The statement originated in tish-gba, and deck-player later added its own copy, but the reference host never had one — so a .deck carrying a named table failed to load with unexpected top-level: wave, and the DMG wave channel offered three hardcoded shapes and nothing else. There was no way to author a wavetable here at all.

wave is core grammar now, which resolves both spellings to 32 levels before Deckard sees them:

wave organ 8beffecbbbbaa9888776554444310014
wave organ harmonics 1 0.5 0.33 0.2

What this adds

• Project model holds the tables by name, keeping mode / harmonics / hex alongside levels.
• Apply collects them and points each channel at the table its wave_shape names. A UI knob turn arrives as a one-track .deck fragment through this same path, so the binding stays correct when the shape is changed by hand rather than only on load.
• GameBoyDmg plays a named table in preference to the built-in shapes — the same named_waves.get(wave_shape).unwrap_or_else(built_in) order the GBA bake uses. Levels are already on the 16-level grid wave RAM holds, so unlike the built-ins they need no quantization step.
• The Wave selector lists the song's tables instead of only Saw/Square/Sine. A shape the song names but has no table for stays selectable, so turning the knob can't silently rewrite it.
• Emit writes the tables back — and writes a harmonics line as harmonics rather than flattening it to 32 digits. That is the whole point of the parser keeping the source spelling: a save should not throw away what the author wrote. Only tables a channel actually names are emitted, or a project would accumulate a dead wave line every time it loaded a file.

Verification

New test/wavetables.tish (wired into test:js), 12 assertions covering: both spellings collected, harmonics resolving to the same levels as its hex literal, channel binding, harmonics surviving emit unflattened, hex emitting as hex, unused tables not emitted, a full round trip preserving levels and mode, and a built-in shape name binding no table.

Existing suites unchanged: PASS=516, 279, 278, 52, 13, 12, 11, 7, all with FAIL=0.

Note this repo's origin is an HTTPS URL, so the branch was pushed over SSH.

[spacedevin]

Unblocked and out of draft — on the released @spacedevin/deck 1.5.3 (up from ^1.3.0).

Everything now verifies against a real install rather than a linked local build:

• test/wavetables.tish — all 12 pass
• existing suites unchanged: PASS=516, 279, 278, 52, 13, 12, 11, 7, all FAIL=0