TS: Slice setters for max:* slices should accept arrays, not single elements

[ryukzak]

Currently, slice setters like setOrganizationEntry() accept a single element and use setArraySlice() which replaces by discriminator match. For slices with max: * (unbounded), this means:

bundle
    .setOrganizationEntry({ resource: org1 })
    .setOrganizationEntry({ resource: org2 });
// Result: only org2 — the second call replaces the first

This is wrong for unbounded slices. The setter should accept an array:

// Desired API for max:* slices
bundle.setOrganizationEntry([
    { resource: org1 },
    { resource: org2 },
]);

The getter should also return an array for max:* slices.

For updating, the pattern should support spread:

bundle.setOrganizationEntry([
    ...bundle.getOrganizationEntry(),
    { resource: newOrg },
]);

Current behavior

• setOrganizationEntry(entry) — replaces the single matched slice element (upsert by discriminator)
• getOrganizationEntry() — returns the first matched element

Expected behavior

For slices with max: 1 (e.g. PatientEntry): current single-element API is correct.

For slices with max: * (e.g. OrganizationEntry):

• setOrganizationEntry(entries[]) — replaces all matched slice elements with the provided array
• getOrganizationEntry() — returns all matched elements as an array

Scope

• Affects src/api/writer-generator/typescript/profile-slices.ts (setter/getter generation)
• Needs to branch on sliceDef.array / max cardinality when generating the setter signature and implementation
• Affects profile-helpers.ts — may need a setArraySliceAll / getArraySliceAll helper