Replace Go backend with .NET 10 — Go compiler crashes freeze Proxmox host

[BrewingCoder]

Problem

The Go compiler repeatedly crashes when compiling the gqlgen-generated generated.go file (88,298 lines / 2.8MB). This has caused three Proxmox host freezes, taking down DNS/DHCP for the entire network. The crashes occur during:

1. gqlgen generate — SIGBUS/page fault during codegen
2. go test -coverprofile — coverage-instrumented compilation exhausts memory
3. CodeQL Go analysis — compiles the full backend

Remediation steps attempted:

• Upgraded gqlgen v0.17.70 → v0.17.88
• Upgraded Go to 1.25 (newer compiler)
• Disabled runner-2 (single runner only)
• Cleaned Go build/test caches on runner
• Bumped VM RAM 8GB → 16GB
• Split generated.go into smaller files (held in reserve)

Steps 1-4 fixed gqlgen and CodeQL crashes, but go test -coverprofile (SonarQube backend analysis) still crashes the host. The runner is currently stopped and disabled to protect network stability.

Root cause

A single 88K-line generated file is an unreasonable demand on the Go compiler's memory. This is a fundamental architectural problem with gqlgen's code generation approach.

Solution

Replace the Go backend with .NET 10 / EF Core 10 using Hot Chocolate for GraphQL. Hot Chocolate is code-first with zero codegen — the 88K-line file problem cannot exist.

See docs/GRAPHQL-ALTERNATIVES.md for full alternatives analysis and docs/DOTNET-MIGRATION-PLAN.md for the detailed replacement plan.

Scope

• Phase 0: Scaffold .NET solution, mirror EF Core models from GORM, verify parity
• Phase 1: Private GraphQL (dashboard API) via Hot Chocolate
• Phase 2: Public GraphQL (data ingestion) via Hot Chocolate
• Phase 3: Kafka workers as BackgroundServices
• Phase 4: Integrations + Auth
• Phase 5: Cut over, remove Go backend

Acceptance criteria

• .NET solution compiles and runs
• EF Core models match PostgreSQL schema
• Hot Chocolate serves private GraphQL queries
• No codegen files, no compiler crashes
• CI runs without crashing the host

[github-actions]

AI Triage: Proposal to replace Go backend with .NET 10/Hot Chocolate to eliminate compiler crashes caused by massive gqlgen-generated files that freeze the CI host.

Labels applied: area:backend, tech-debt, priority:high, priority:critical, component:graphql