Start work on device flow login + backend performance improvements

[Mirabliss]

This PR initializes the feature branch for the requested work:\n\n- Batch processing in the Go ingest service for peak traffic handling\n- Connection pooling optimization for PostgreSQL read replicas and PgBouncer\n- Redis-based caching for high-traffic endpoints\n- Supporting CLI login with device flow\n\nThis is an initial branch setup commit.

[drips-wave]

Hey @Mirabliss! 👋 It looks like this PR isn't linked to any issue.

If this PR is for one of the issues assigned to you as part of a Wave, please link it to ensure your contribution is tracked properly. You can do this by adding a keyword to the PR description (e.g., Closes #123), or by clicking a button below:

Issue	Title
#277	Create Video Tutorial Series for Key Features	Link to this issue
#279	Implement Connection Pooling for PostgreSQL Read Replicas	Link to this issue
#278	Implement Query Result Caching for High-Traffic Endpoints	Link to this issue
#284	Add Batch Processing for High-Volume Transaction Ingestion	Link to this issue

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