docs(architecture): add Phase 0 architecture specs for ALPN-as-service model
Foundational architecture documents following the SDD process:
ADRs:
- 001: ALPN-based protocol dispatch (one endpoint, ALPN negotiation)
- 002: ProtocolHandler trait (replaces StreamInterface/MessageInterface)
- 003: Crate decomposition (one crate per handler, core provides shared infra)
- 004: Auth as shared core (IdentityProvider, hybrid resolution model)
- 005: irpc as call protocol foundation
- 006: ALPN string convention and connection model (alknet/ prefix, one ALPN per connection)
Docs:
- overview.md: crate graph, shared types, ALPN registry, failure modes
- README.md: index with doc table, ADR table, lifecycle definitions
- open-questions.md: 10 OQs across 7 themes (3 resolved, 7 open)
Crate spec stubs for all 11 planned crates (alknet-core through alknet CLI).
Key decisions resolved during self-review:
- AuthContext resolution is hybrid: endpoint resolves TLS-level auth,
handlers resolve protocol-level auth (resolves OQ-02)
- ALPN is per-connection not per-stream, corrected ADR-001 (resolves OQ-06)
- ALPN naming uses alknet/ prefix without versions (resolves OQ-03)
- HandlerError return type on ProtocolHandler trait
- alknet/secret removed from ALPN registry until OQ-08 resolved
glm-5.1
f77b515968