fix: improve type safety in follow.ts by removing any usages (#550)

[yachikadev]

Summary

Removes all remaining any usages from follow.ts and replaces them with proper Fastify and JWT types, reusing the existing type definitions in src/types/fastify.d.ts.

Changes

• Removed request.server as any and (app as any).authenticate casts — FastifyInstance.authenticate and request.server are already properly typed via the existing fastify.d.ts augmentation, so no casts are needed.
• Replaced (request as any).user = payload with request.user = payload, typing the JWT payload using request.jwtVerify<AuthenticatedUser>() (imported from ../types/fastify.js) so it matches the AuthenticatedUser type already declared for request.user.
• Replaced all three (request.user as any).id usages with request.user.id.
• Replaced catch (error: any) with catch (error) and used the existing getErrorMessage utility, matching the error-handling pattern already used elsewhere in this file.

Testing

• npx tsc --noEmit passes with no errors.
• Follow route tests: 16/16 passing.

Closes #550

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[github-actions]

Hi @yachikadev,

Thanks for opening this pull request.

This PR has been automatically classified based on the files modified.

Applied Labels

• gssoc:approved
• backend

Primary Review Area

• backend

Reviewer

@Harxhit has been identified as the primary reviewer for this pull request.

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Thank you for your contribution!

[github-actions]

CI — All Checks Passed

Backend — PASS

Check	Result
Lint	PASS
Test	PASS
Typecheck	PASS

Mobile — SKIP

Check	Result
Lint	-
Test	-

Web — SKIP

Check	Result
Check	-
Build	-

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Last updated: Sun, 14 Jun 2026 12:48:10 GMT

[Harxhit]

LGTM. Approving

[github-actions]

Congratulations @yachikadev on getting PR #575 merged!

Thank you for your contribution to the project.

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