Resolve the client fork and adopt the published frontend platform

[w4ffl35]

Context

spikeforge/client and the local snn_interpreter/client are byte-identical at the package-manifest level and share a large source surface, while spikeforge has since gained additional components. The goal is one maintained client capability, not two copied trees.

Work

• Confirm spikeforge remains the canonical source and record the provenance of snn_interpreter.
• Compare routes, types, hooks, protocol code, and components; classify each difference as upstreamable, product-specific, generated, or obsolete.
• Extract shared client code into a package or workspace member only where release cadence supports it.
• Adopt @capsizellc/commons for non-visual utilities and @capsizellc/ui for visual primitives after publication.
• Preserve the existing dashboard/hub API contracts and test the client against them.
• Add a migration/rollback note for the local snn_interpreter tree and coordinate 999 consumers before any retirement.

Acceptance criteria

No source file is silently dropped; the canonical client path is documented; at least one consumer uses the shared package rather than a copied directory; browser tests/typechecks pass; and snn_interpreter remains recoverable until the provenance gate is explicitly closed.

Coordinate with Capsize-Games/hq#5, #24, #30, #34, and #35.