Implement ComparisonShare serving and sharing URLs for property comparison

[nanaf6203-bit]

Context

schema.prisma has ComparisonShare (shareable comparison links with token/expiry) created by property-comparison.service.ts; ComparisonShare is otherwise unexposed.

Problem

The data model and generation logic exist but there is no read/share endpoint: shared links can't be loaded or expire; the model is effectively dead outside of property-comparison creation tests, contradicting the module's purpose to let users share comparisons.

Proposed approach

Add GET /property-comparison/shares/:token returning the two compared properties (public, without owner PII), enforce expiresAt/revokedAt, and track share views; add e2e for valid/expired/revoked tokens.

Acceptance criteria

• Shared links resolve correctly and expire; coverage added.

[damiedee96]

@damiedee96 has applied to work on this issue as part of the Stellar Wave Program's 9th wave.

Hello Maintainer, I'd love to work on this issue.

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[beulah7717108-eng]

@beulah7717108-eng has applied to work on this issue as part of the Stellar Wave Program's 9th wave.

Hello Maintainer

please kindly assign me this issue to fix

ℹ️ Repo Maintainers: To accept this application, review their application or assign @beulah7717108-eng to this issue.

[drips-wave]

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