Normalize reused string-literal property names to identifiers in declaration emit

[Copilot]

Declaration emit produced inconsistent property-name quoting when a nested object type was reused from source: top-level properties (rebuilt via typeToTypeNode) emitted as identifiers, while nested properties (reused via pseudoTypeToNode) preserved the user's string-literal form even when the text was a valid identifier.

export const platformSlice = createSlice({
    "query": { "search": "", "user": "" },
});

// Before
export declare const platformSlice: {
    query: {
        "search": string;
        "user": string;
    };
};

// After
export declare const platformSlice: {
    query: {
        search: string;
        user: string;
    };
};

Changes

• internal/checker/nodecopy.go — reuseName now normalizes a reused StringLiteral whose text is a valid identifier into an Identifier, matching createPropertyNameNodeForIdentifierOrLiteral used on the fresh-construction path. The name "new" is excluded so reused "new"(): void method signatures aren't rewritten into construct signatures (mirroring the existing isMethodNamedNew guard).
• Baselines — Two existing submodule baselines (escapedReservedCompilerNamedIdentifier.js, jsDeclarationsPackageJson(target=es2015).types) now match strada exactly; their .diff files and the corresponding submoduleAccepted.txt entry were removed.
• New test — testdata/tests/cases/compiler/declarationEmitStringNamedPropertyConsistency.ts covers the reported repro.