fix(pg-wasm): omit default-module-path in web wasm-bindgen glue (#153)

[dobby-coder]

Summary

wasm-pack build --target web (shipped as @e4a/pg-wasm) generated an unreachable default-module-path branch in __wbg_init:

if (module_or_path === undefined) {
    module_or_path = new URL('index_bg.wasm', import.meta.url);
}

Webpack 5 statically analyzes new URL("...", import.meta.url) as an asset import and tries to resolve index_bg.wasm at build time — even though the branch never fires for callers that always pass module_or_path explicitly (e.g. @e4a/pg-js, which inlines the WASM as base64). Downstream consumers therefore hit Module not found: Can't resolve 'index_bg.wasm'.

Fix

Enable wasm-bindgen's --omit-default-module-path (the issue's preferred option 1) via wasm-pack's release-profile metadata in pg-wasm/Cargo.toml:

[package.metadata.wasm-pack.profile.release.wasm-bindgen]
omit-default-module-path = true

wasm-pack does support this flag through manifest metadata (confirmed on wasm-pack 0.15.0, the version CI installs), so the branch is never generated in the first place. This keeps the fix in the crate manifest — no workflow change and no fragile post-build regex strip against generated output.

This supersedes #199, which stripped the branch with a post-build node regex in delivery.yml. That approach works but (a) is a workflow-only change and (b) matches generated output by pattern. This PR uses the actual --omit-default-module-path flag instead, so it's robust to wasm-bindgen formatting changes and touches only Cargo.toml.

Verification (locally, wasm-pack 0.15.0)

• Before: pg-wasm/pkg/web/index.js contains the new URL('index_bg.wasm', import.meta.url) branch (lines 1235–1237).
• After: rebuilding --target web with the metadata → zero index_bg.wasm / new URL(...) references; __wbg_init retains the explicit-module_or_path path (object-unwrap + string | Request | URL → fetch). Callers passing module_or_path are unaffected; a caller passing nothing now errors at instantiate time, exactly as --omit-default-module-path intends.
• Bundler target unaffected: it emits import * as wasm from "./index_bg.wasm" (a legitimate static module import, not the import.meta.url asset pattern) with no __wbg_init — so no dead branch exists there and none is introduced. This corrects fix-option 2 in the issue body.
• cargo metadata parses the manifest; cargo fmt --all -- --check clean (no Rust changed). package.metadata is ignored by cargo, so the Rust test suite is unaffected; the wasm-pack build --release runs for both targets (the exact CI code path) succeed.

Downstream

Once a new @e4a/pg-wasm ships with this, @e4a/pg-js only needs a dep bump + republish, and the parser: { url: false } webpack workaround in downstream consumers can be removed.

Fixes #153

🤖 Generated with Claude Code

[dobby-coder]

Rules Dobby 2 gatekeeper review — cycle 1. 0 confirmed findings; clean.

Per-rule Haiku sweep merged with Review Dobby 2's findings (0). The diff is textbook-correct against our own memory (postguard-wasm-pack-omit-default-module-path): wasm-pack 0.15.0 honors omit-default-module-path via [package.metadata.wasm-pack.profile.release.wasm-bindgen], the bundler target correctly needs no change, and cargo ignores package.metadata so the build is the check — verified: --target web now emits 0 index_bg.wasm / new URL(import.meta.url) refs while the explicit module_or_path fetch path is retained.

Two Haiku-raised flags reviewed and dismissed: (1) tests-required — the metadata is cargo-ignored, so there is no testable unit; build-output verification is the correct and completed check; (2) justification-comment — the comment documents a non-obvious webpack static-resolution interaction a maintainer needs to keep the flag, not a rationale-narration of a self-evident deletion.

Submitted as COMMENT (APPROVE is rejected on a self-authored PR); routing on findings = clean → ready-for-review.