Consider using `-sSINGLE_FILE=1` to simplify the WASM build plumbing

[tameware]

Per Cursor:

Here’s what adopting -sSINGLE_FILE=1 would look like in this repo — a sketch, not a patch.

Build

Add the flag next to the other MVP linkopts, and drop the separate .wasm from declared outputs (or keep it knowing Bazel may emit an empty placeholder):

# web/BUILD.bazel
WASM_MVP_LINKOPTS = WASM_LINKOPTS + [
    "-sMODULARIZE=1",
    "-sEXPORT_NAME=createDdsModule",
    "-sSINGLE_FILE=1",  # wasm base64-inlined into the .js
    # ...existing EXPORTED_* / ENVIRONMENT...
]

wasm_cc_binary(
    name = "dds_mvp_wasm",
    cc_target = ":dds_mvp_wasm_cc",
    threads = "emscripten",
    outputs = [
        "dds_mvp_wasm.js",
        # no separate .wasm when SINGLE_FILE works as expected
    ],
)

Emscripten then emits one .js with the wasm embedded (base64 data URL). Your custom gen_wasm_bin_js.py becomes redundant for the same job.

Load path (the real cleanup)

Today:

dds_mvp_wasm_bin.js  →  ddsMvpWasmBytes()
dds_mvp_wasm.js      →  createDdsModule({ wasmBinary: ... })

With SINGLE_FILE:

<!-- dds_mvp.html: drop bin.js -->
<script src="dds_mvp_wasm.js"></script>
<script src="dds_mvp.js"></script>

// dds_mvp.js — createDdsModule() with no wasmBinary
ddsModulePromise = createDdsModule({ /* defaults load inlined wasm */ })

Remove the ddsMvpWasmBytes guard.

Scripts / staging

Piece	Change
update_wasm.sh	Copy only .js; drop gen_wasm_bin_js.py and .wasm copy; keep surgical patch_mvp_wasm.py
clean_wasm.sh / .gitignore	Stop tracking dds_mvp_wasm.wasm / *_bin.js
mvp_site.py	Stage + patch .js only; delete bin.js generation
verify_wasm_js.py	Either decode the inlined base64 from the .js, or drop / rewrite verification
dds_mvp_wasm_node.mjs	createDdsModule() with no wasmBinary / no WASM_FILE arg
System / e2e tests	Drop ddsMvpWasmBytes checks and wasm path wiring

patch_mvp_wasm.py stays — it already assumes SINGLE_FILE and only rewrites the one isFileURI match (global replace would corrupt the embedded bytes).

What does not go away

• Pthreads / COOP+COEP — still required; serve_mvp.py unchanged.
• MODULARIZE + createDdsModule — still the app contract.
• Worker bootstrap — with -pthread, Emscripten may still emit a separate worker helper; don’t assume a single file covers every artifact.
• Bazel quirk — wasm_cc_binary historically materializes empty siblings for undeclared optional outputs; validate that dropping "….wasm" from outputs doesn’t break the rule, or leave a dummy and ignore it.

Size / DX tradeoff

You trade three artifacts + a Python embed step for one larger .js (wasm × ~4/3 from base64). Cache invalidation becomes coarser (any C++ change busts the whole glue file). Functionally it’s the same idea you already have with dds_mvp_wasm_bin.js, just done by the linker.

Net: mostly deleting the bin.js pipeline and simplifying load/tests; the build flag itself is a one-liner. Worth doing only if you want less custom plumbing — not for new capability you don’t already have via base64 embed.