Clean up rebranding drift in docs, agent configs, and source comments

Fix stale references left over from the alknet-typedef → alktype migration:
- .opencode/agents/: replace @alkdev/alknet constraints (tokio, crypto, feature
  flags, anyhow/thiserror) with alktype-accurate ones (sync, AlkTypeError,
  WASM-clean); fix @alkimiadev → @alkdev org name; remove nonexistent AGENTS.md
  ref; replace alknet-http/alknet-agent spec examples
- docs/sdd_process.md: fix wrong package name (@alkdev/storage → @alkdev/alktype)
- docs/architecture/: rewrite dangling /workspace/ and docs/research/ paths as
  @alkdev/alknet: cross-repo references with explanatory notes; fix
  @alkimiadev → @alkdev; fix 'not yet used by any alknet crate' stale context
- src/ + tests/: correct '17 AlkType kinds' → '19' in doc comments (enum has 19
  variants; pre-existing count error); fix dangling /workspace/ path in
  poc_roundtrip.rs

docs/architecture/data-access.md

@@ -377,8 +377,9 @@ See [open-questions.md](open-questions.md) for full details.
 
 ## References
 
-- `docs/research/alknet-typedef/findings.md` §"POC Results" — POC 1
-  (read/write round-trip) and POC 2 (SFTP byte-identical round-trip)
+- `@alkdev/alknet: docs/research/alknet-typedef/findings.md` §"POC Results"
+  — POC 1 (read/write round-trip) and POC 2 (SFTP byte-identical
+  round-trip)
 - [layout-engine.md](layout-engine.md) — offset computation that produces
   the positions this layer reads/writes at
 - [validation.md](validation.md) — validation that runs on the same