Fix invalid TypeScript definitions causing TS2309 and TS2451 errors

[Copilot]

• Understand the issue: TypeScript definitions file has invalid syntax
  • export = Bowser; conflicts with ES6 named exports (TS2309)
  • Constants are declared twice (module level and inside namespace) (TS2451)
• Reproduce the issue by compiling with skipLibCheck: false
• Fix the TypeScript definitions file:
  • Removed export = Bowser; line (resolves TS2309)
  • Changed declare namespace Bowser with inner namespace Parser to export namespace Parser (resolves TS2451)
  • Removed duplicate constant declarations from the former Bowser namespace
  • Removed duplicate method declarations in Parser interface (isBrowser, isEngine, isOS, isPlatform)
• Test the fix with TypeScript compiler
• Run code review and address feedback
• Run security checks (no vulnerabilities found)
• Revert package.json changes (removed TypeScript dev dependency)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>typescript definitions are invalid</issue_title>
<issue_description>In a bare angular 20 app with skipLibCheck set to false in tsconfig, bowser 2.13.0 generates these build errors:

✘ [ERROR] TS2309: An export assignment cannot be used in a module with other exported elements. [plugin angular-compiler]

    node_modules/bowser/index.d.ts:5:0:
      5 │ export = Bowser;
        ╵ ~~~~~~~~~~~~~~~~


✘ [ERROR] TS2451: Cannot redeclare block-scoped variable 'BROWSER_MAP'. [plugin angular-compiler]

    node_modules/bowser/index.d.ts:10:13:
      10 │ export const BROWSER_MAP: Record<string, string>;
         ╵              ~~~~~~~~~~~

  'BROWSER_MAP' was also declared here.

    node_modules/bowser/index.d.ts:35:8:
      35 │   const BROWSER_MAP: Record<string, string>;
         ╵         ~~~~~~~~~~~


✘ [ERROR] TS2451: Cannot redeclare block-scoped variable 'ENGINE_MAP'. [plugin angular-compiler]

    node_modules/bowser/index.d.ts:11:13:
      11 │ export const ENGINE_MAP: Record<string, string>;
         ╵              ~~~~~~~~~~

  'ENGINE_MAP' was also declared here.

    node_modules/bowser/index.d.ts:36:8:
      36 │   const ENGINE_MAP: Record<string, string>;
         ╵         ~~~~~~~~~~


✘ [ERROR] TS2451: Cannot redeclare block-scoped variable 'OS_MAP'. [plugin angular-compiler]

    node_modules/bowser/index.d.ts:12:13:
      12 │ export const OS_MAP: Record<string, string>;
         ╵              ~~~~~~

  'OS_MAP' was also declared here.

    node_modules/bowser/index.d.ts:37:8:
      37 │   const OS_MAP: Record<string, string>;
         ╵         ~~~~~~


✘ [ERROR] TS2451: Cannot redeclare block-scoped variable 'PLATFORMS_MAP'. [plugin angular-compiler]

    node_modules/bowser/index.d.ts:13:13:
      13 │ export const PLATFORMS_MAP: Record<string, string>;
         ╵              ~~~~~~~~~~~~~

  'PLATFORMS_MAP' was also declared here.

    node_modules/bowser/index.d.ts:38:8:
      38 │   const PLATFORMS_MAP: Record<string, string>;
         ╵         ~~~~~~~~~~~~~


✘ [ERROR] TS2451: Cannot redeclare block-scoped variable 'BROWSER_MAP'. [plugin angular-compiler]

    node_modules/bowser/index.d.ts:35:8:
      35 │   const BROWSER_MAP: Record<string, string>;
         ╵         ~~~~~~~~~~~

  'BROWSER_MAP' was also declared here.

    node_modules/bowser/index.d.ts:10:13:
      10 │ export const BROWSER_MAP: Record<string, string>;
         ╵              ~~~~~~~~~~~


✘ [ERROR] TS2451: Cannot redeclare block-scoped variable 'ENGINE_MAP'. [plugin angular-compiler]

    node_modules/bowser/index.d.ts:36:8:
      36 │   const ENGINE_MAP: Record<string, string>;
         ╵         ~~~~~~~~~~

  'ENGINE_MAP' was also declared here.

    node_modules/bowser/index.d.ts:11:13:
      11 │ export const ENGINE_MAP: Record<string, string>;
         ╵              ~~~~~~~~~~


✘ [ERROR] TS2451: Cannot redeclare block-scoped variable 'OS_MAP'. [plugin angular-compiler]

    node_modules/bowser/index.d.ts:37:8:
      37 │   const OS_MAP: Record<string, string>;
         ╵         ~~~~~~

  'OS_MAP' was also declared here.

    node_modules/bowser/index.d.ts:12:13:
      12 │ export const OS_MAP: Record<string, string>;
         ╵              ~~~~~~


✘ [ERROR] TS2451: Cannot redeclare block-scoped variable 'PLATFORMS_MAP'. [plugin angular-compiler]

    node_modules/bowser/index.d.ts:38:8:
      38 │   const PLATFORMS_MAP: Record<string, string>;
         ╵         ~~~~~~~~~~~~~

  'PLATFORMS_MAP' was also declared here.

    node_modules/bowser/index.d.ts:13:13:
      13 │ export const PLATFORMS_MAP: Record<string, string>;
         ╵              ~~~~~~~~~~~~~
```</issue_description>

## Comments on the Issue (you are @copilot in this section)

<comments>
<comment_new><author>@naorpeled</author><body>
Investigating this 🙏 </body></comment_new>
</comments>

• Fixes typescript definitions are invalid #589

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[naorpeled]

@copilot please revert package.json changes

[Copilot]

@copilot please revert package.json changes

Reverted in 50faa20. Removed the TypeScript dev dependency that was added during testing.

[Copilot]

Copilot wasn't able to review any files in this pull request.