chore: upgrade Elixir/OTP to match Console and switch to Mix releases

[zreigz]

Replace Distillery with Mix releases and align Phoenix/Ecto with the Console toolchain (Elixir 1.19.4 / OTP 28.5).

Test Plan

Checklist

• If required, I have updated the Plural documentation accordingly.
• I have added tests to cover my changes.
• I have added a meaningful title and summary to convey the impact of this PR to a user.
• I have added relevant labels to this PR to help with categorization for release notes.

[linear]

PROD-5133

[greptile-apps]

Greptile Summary

The PR upgrades the umbrella to Elixir 1.19.4/OTP 28.5, refreshes Phoenix/Ecto and related dependencies, and replaces Distillery packaging with role-specific Mix releases.

• Adds Mix releases and runtime configuration for API, RTC, worker, and cron roles.
• Updates Docker, Helm, CI, and local Compose workflows for the new release layout.
• Migrates several library integrations, including Guardian, Gettext, Waffle, Sentry, and Influx.

Confidence Score: 3/5

The PR should not be merged until the local RabbitMQ management endpoint is restricted to localhost or otherwise protected from network access.

The release conversion is internally aligned, but the newly documented local stack exposes a message-broker administrator interface with publicly known credentials, allowing network users to manipulate local queues and messages.

Files Needing Attention: docker-compose.stack.yml

Security Review

The new local Compose stack exposes RabbitMQ’s administrative interface on all host interfaces using committed administrator credentials. Restrict the binding to localhost or avoid publishing the management port before using this workflow on network-reachable hosts.

Important Files Changed

Filename	Overview
mix.exs	Defines four role-specific Mix releases with matching runtime configuration paths and application sets.
Dockerfile	Replaces Distillery extraction with named Mix-release builds and copies the selected release into the runtime image.
rel/runtime/plural.exs	Supplies environment-driven runtime configuration for the main API release while preserving the compiled endpoint server settings.
apps/core/lib/core/influx.ex	Replaces the Instream connection process with a Req-based compatibility client; no concrete caller-visible regression was established.
apps/api/lib/api_web/plugs/remote_ip.ex	Adapts forwarding-header parsing to RemoteIp 1.2 while retaining the pre-existing trust model and downstream IP behavior.
docker-compose.stack.yml	Adds a useful local release stack, but exposes RabbitMQ administration beyond localhost using static administrator credentials.
plural/helm/plural/templates/migration.yaml	Updates the database migration job to invoke the overlay command included in the plural Mix-release image.

_{Reviews (1): Last reviewed commit: "chore: upgrade Elixir/OTP to match Conso..." | Re-trigger Greptile}

[michaeljguarino]

I suspect this is mostly correct, we need to test it in dev for sure though, I'll handle that with the test images built.