v3.5.0 — The Neuron

[3.5.0] — 2026-07-18 — The Neuron — on-device concierge, ported to all 8 languages + multilingual docs

Adds the Neuron: a private, on-device second brain that decides, per turn,
whether an always-warm generalist answers or a capability-matched specialist is
hot-loaded to answer — grounded in one shared memory and persona, host-neutral,
and durable across restarts. Built on the C# reference and ported to all seven
sister languages (Python, TypeScript, Go, Kotlin, Swift, Rust, C), each adapted
to its substrate and covered by its own tests. HarmonyOS remains the single
documented gap. Also ships a multilingual README set — the Neuron explained in
17 languages, including six new African-language translations.

Added — the Neuron (CircleAI.Hosting, mirrored to all 7 ports)

• Concierge router + gate — INeuronRouter / HeuristicNeuronRouter /
  NeuronGate. Per-turn keyword/length heuristics (never a model) route each
  turn to the generalist or a specialist (vision / long-context / reasoning);
  a gate can veto a specialist, and the generalist floor always answers.
• Two-slot residency — ResidentSlotManager, a RAM admission gate that
  keeps the generalist warm and hot-loads at most one specialist beside it,
  reserving RAM before loading and evicting the specialist first under
  memory pressure so the generalist never drops. Wired into AIService at the
  chat / stream / agentic call sites, gated on AIOptions.Router — with no
  router the path is byte-identical to before.
• Host-neutral seam + facade — IChatRuntime / IPersistableChatRuntime
  • NeuronNode, so any harness can drive the node without touching engine
    internals; AddNeuron(...) DI; generalist-floor KV session save/load for
    OOM/restart survival.
• Voice — the "Hey B" voice loop drives the Neuron (NeuronVoice).
• Ported to all seven sister languages — Python, TypeScript, Go, Kotlin,
  Swift, Rust, C. Each adapts to its substrate (rich ports mirror the two-slot
  path directly; thinner ports inject a specialist selector + factory; C ships
  a self-contained module over its callback substrate) and carries its own
  Neuron test suite.

Added — documentation + internationalisation

• Plain-language Neuron section in the root README — what it is, and how a
  network of Neurons composes (clearly marked as not-yet-built vision).
• 17-language README set under docs/i18n/: a new English source, the
  Neuron section added to the 10 existing translations (Arabic, German,
  Spanish, Persian, French, Japanese, Korean, Portuguese-BR, Russian, Chinese),
  and six new African-language READMEs — Afrikaans, Kiswahili, isiZulu,
  Sesotho, Hausa, Amharic — matching the product's own language support. A
  language bar links them all from the root README.

Notes

• Neuron unit tests verified green per language: C# (net9 and net10),
  Python, Go, Rust (16/16), TypeScript (17/17), Kotlin (17/17), Swift (17/17 on
  macOS), C (full CMake library build + ctest). AIOptions.Router null keeps
  every existing AIService path byte-identical.
• The docs/i18n translations are AI-assisted starting points; native-speaker
  review is welcome, isiZulu especially.