chore(prisma): upgrade Prisma ecosystem to 7.8.0

[kattsushi]

Problem

The Effect Prisma package is pinned to Prisma 7.3.0, including its client, generator internals, runtime utilities, and database adapters. Generated Effect files also include wall-clock timestamps, making repeated generation nondeterministic.

Proposed solution

• Upgrade the coordinated Prisma dependency cohort to stable 7.8.0.
• Keep prisma-client-js and existing public Effect Prisma contracts.
• Remove volatile timestamps from generated file headers while retaining the generated-file warning.
• Regenerate the lockfile and validate the package plus all Prisma-consuming examples.

Acceptance criteria

• Prisma CLI, client, adapters, runtime utilities, and generator packages resolve coherently to 7.8.0.
• Repeated canonical generation is deterministic.
• Effect Prisma, React Router, Remix, and node-auth supported checks pass through Nx.
• Existing public imports and generator provider remain compatible.

Pre-flight checks

• Existing issues were searched and no duplicate was found.
• This issue is approved for the implemented maintenance work.

[kattsushi]

Completed by merged PR #69 and superseded by the verified Prisma 7.9.1 upgrade in merged PR #153.