trace-schemas: add namespace-driven schema generation and validation tooling

[jutaro]

Description

Summary

This PR introduces a namespace-driven trace schema workflow and the tooling around it.

It adds support for generating schema files from traced namespaces, validates generated schemas and trace logs, documents how overrides work, and wires the schema scripts into a standalone Cabal package so they can be run consistently from the dev environment. It also updates trace documentation generation to work with optional namespace lists and refreshes the generated trace-schema artifacts.

On the tracing side, it extends the source discovery and inference logic used by schema generation, improves handling of external trace-dispatcher definitions, and tightens warning reporting so schema generation only reports real unresolved cases instead of false positives.

Why this is hard

This cannot be solved by deriving JSON Schema directly from Haskell types, because the trace JSON is not determined by the types alone. The emitted payloads are shaped by forMachine implementations, helper functions, pattern matches, namespace mapping, verbosity/detail levels, and hand-written rendering logic across multiple packages. In practice, fields may be renamed, omitted, flattened, synthesized, or rendered as strings, so the runtime JSON contract often differs from the source type definition.

Main changes

• Add bench/trace-schemas as the home for generated schemas, metadata, documentation, presentations, and helper docs.
• Add schema-generation tooling:
  • GhciSchemaGen.hs
  • ValidateTraceSchemas.hs
  • ValidateTraceLog.hs
  • ApplySchemaOverrides.hs
  • CheckOverrideCoverage.hs
  • RegenerateTraceSchemas.sh
• Add trace-schema-gen.cabal and wire it into cabal.project.
• Add override documentation and examples for human-maintained schema patches.
• Update cardano-node trace documentation generation to support optional namespace selection.
• Improve namespace/source resolution and schema inference across cardano-node, trace-dispatcher, and related tracing modules.
• Regenerate newNamespaces.txt, trace-documentation.md, and schema artifacts from the new pipeline.
• Guard destructive override application by default.
• Tighten schema-generation warnings so only genuinely empty/unresolved final schemas are reported.

Testing

• Ran schema generation through nix develop.
• Ran override application and check scripts.
• Verified the updated generator completes with Schema generation problems: 0.

[mgmeier]

Please condense / clean-up commit history for this PR.

[mgmeier]

Testing feedback: You've already made the various scripts executables in bench/trace-schemas/scripts/schema-gen/trace-schema-gen.cabal. This means, they're part of the nix flake.

So instead of building a full dev shell with all dependencies, and running the script via bash / runghc, you should switch the new Make targets to something like nix run .#schema-gen.