Update extension templates to Bundler module resolution

[akhayoon]

Background

Resolves shop/issues-retail#33804.

Generated POS Preact extensions import @shopify/ui-extensions/preact, but their legacy Node10 module resolution does not understand that package's modern exports entry. TypeScript 6 also rejects the deprecated node resolution mode with TS5107.

Solution

Replace "moduleResolution": "node" with "moduleResolution": "Bundler" in every generated extension configuration that still uses the legacy resolver.

This is intentionally a resolver-only change:

• All 18 affected templates keep their existing target and noEmit settings, and continue to omit module.
• No explicit module policy is introduced by this PR.
• The existing discount settings template remains unchanged on ESNext plus Bundler.
• TypeScript 5 or newer is required because Bundler was introduced in TypeScript 5.

Existing generated projects are not modified.

The exact tested head is d5352b09dc5f4a05cb053be7812f1dd4c9862771.

Testing

Verified from exact base c05f026ad348e1c340b06effe6ba7a51ee0cffab against the final candidate:

• The final diff is exactly 18 moduleResolution replacements from node to Bundler, with no other changed lines.
• Shopify CLI 4.7.1 rendered all 134 registry selections represented by 74 unique path/flavor pairs twice. Each side produced 550 deterministic files.
• The 17 registry-reachable changed configurations plus the unregistered Preact Liquid branch retain target: ES2020, omit module, use moduleResolution: Bundler, and retain noEmit: true.
• TypeScript 5.0.4, 5.9.3, and 6.0.3 accept the options in every migrated configuration. Current-head and resolver-only candidate source diagnostics are identical for all 17 reachable configurations under all three compilers.
• For an exact generated POS Preact extension, TypeScript 5.9.3 fails to resolve @shopify/ui-extensions/preact with Node10 and resolves it to the package's exported build/ts/preact.d.ts entry with Bundler.
• TypeScript 6.0.3 reports TS5107 for the base POS configuration and reports no diagnostics for the resolver-only candidate.
• Twenty real shopify app build commands covered all 70 valid generated cases twice: ten current-head controls and ten resolver-only candidate builds. All 75 JavaScript files, 70 source maps, 75 metafiles, and 18 generated declarations were byte-identical between control and candidate and deterministic across repeat builds.
• git diff --check passes. No legacy moduleResolution: "node" setting remains.

TypeScript 4.9 and older cannot read moduleResolution: "Bundler"; TypeScript 5 or newer is the intentional baseline for newly generated extensions.

This PR deliberately leaves module omitted as it was before. TypeScript 5 derives ES2015 from the existing ES2020 target, while TypeScript 6 derives ES2020. Defining a version-independent module syntax policy is separate from this resolver ticket. The affected template sources currently use neither import.meta nor dynamic imports.

Checklist

• I have 🎩'd these changes
• I have squashed my commits into chunks of work with meaningful commit messages

Co-authored by AI.

[henryStelle]

It looks like there are lots more templates with this issue than just ours from https://github.com/search?q=repo%3AShopify%2Fextensions-templates+"moduleResolution"%3A+"node"&type=code. Should we make this a wider update? And if so, use that to align on these being the correct config options (that is what the AI recommended, but I haven't dug into if its right)

[akhayoon]

Great callout @henryStelle. I added for the rest.

[henryStelle]

I looked up these tsconfig options and these look like the correct changes. It would probably be good to get an 👍 from at least one of the other extension teams.

[akhayoon]

Exact-head resolver-only verification

Local read-only reproduction against d5352b09dc5f4a05cb053be7812f1dd4c9862771 after limiting PR #424 to the ticket's resolver change.

• Scope: exactly 18 moduleResolution replacements from node to Bundler; no explicit module additions.
• Ticket witness: TypeScript 6.0.3 reports TS5107 for the generated POS base configuration and no diagnostics for the candidate. TypeScript 5.9.3 changes @shopify/ui-extensions/preact from unresolved under Node10 to its exported declaration under Bundler.
• Rendering: 134 registry selections, 74 unique cases, 550 deterministic files per side, with only the expected 17 reachable configurations plus one unregistered Liquid branch changed.
• Shopify CLI: 20/20 control and candidate build commands passed across 70 valid cases. All 238 compared artifacts per run were byte-identical and repeatable.
• TypeScript: 5.0.4, 5.9.3, and 6.0.3 accept every migrated configuration's options; current-head and candidate source diagnostics match exactly.

These are local reproduction results, not hosted CI or live deployment results.