fix: correct JSDoc comment positioning in type literal members

[benpsnyder]

Problem

Single-line JSDoc comments on type alias members get rendered inline instead of on their own line:

// Input
export type B = {
  /** Comment B1 */
  BA?: string;
  /** Comment B2 */
  BB?: string;
};

// Output (before fix)
type B = {
  /** Comment B1 */BA?: string; /** Comment B2 */
  BB?: string;
};

// Output (after fix)
type B = {
  /** Comment B1 */
  BA?: string;
  /** Comment B2 */
  BB?: string;
};

Interface members are unaffected — only type alias object members have this issue.

Root Cause

Babel's @babel/generator has special-case newline handling for comments inside TSInterfaceBody but not TSTypeLiteral (source). When loc is deleted from AST nodes (which the plugin needs for source map correctness — see e9d69ef), the generator falls through to a heuristic code path that skips newlines before single-line comments in type literals.

Fix

After deleting loc from AST nodes, assign synthetic sequential line numbers to nodes that have leading comments. This steers Babel's generator into the loc-aware code path which correctly inserts newlines before comments regardless of the parent node type. The original comment column positions are preserved to maintain indentation.

Related

• Closes JSDoc comments misplaced in types #182
• Builds on e9d69ef (fix: preserve loc for comment nodes, Incorrect JSDoc indentation for object property comments #168)
• Relevant to Replace rollup with rolldown-plugin-dts for declaration bundling ng-packagr/ng-packagr#3268 (blocking bug for adoption)
• PR fix: detect and internalize types in more cases #175 and PR fix: rewrite local declare module specifiers to output chunk paths #191 also modify fake-js.ts — positional merge conflicts possible, no semantic overlap

Test plan

• New jsdoc-members test fixture covering both interface and type alias members with single-line and multi-line JSDoc comments
• Existing jsdoc test unchanged (no snapshot diff)
• Full test suite passes (197 passed, 1 expected fail)
• No source map regressions