docs(architecture): resolve review #002 Tiers 1-3 — mechanical and consistency fixes

Governance (Tier 2):
- Advance ADR-022 and ADR-023 from Proposed to Accepted (specs already
  depend on their types as source of truth)
- Amend ADR-015: mark Decision 3 and Assumption 6 as superseded by ADR-022;
  update handler_identity type to CompositionAuthority
- Amend ADR-002: note handle() signature revised by ADR-007 (BiStream → Connection)
- Amend ADR-004: note 'enrich/replace' AuthContext language superseded by
  ADR-011's immutability model; update to describe set_identity on Connection
- Update main README ADR table to show ADR-022/023 as Accepted

Spec-ADR consistency (Tier 3):
- Add abort_policy: AbortPolicy field to OperationContext struct (ADR-016
  Decision 6 mandated this but the spec omitted it)
- Define AbortPolicy enum (AbortDependents | ContinueRunning) with Default impl
- Add abort_policy to build_root_context and LocalOperationEnv::invoke()
- Define the OperationEnv trait explicitly with invoke() and
  invoke_with_policy() methods (was referenced as 'must remain a trait'
  but never defined)
- Specify From<StreamError> for HandlerError impl with exact variant mapping
- Add Connection::from_quinn() / from_iroh() constructors (was referenced
  as Connection::new() but never defined)
- Remove undefined CertAuthorityEntry placeholder from AuthPolicy v1 (will
  be added additively when alknet-ssh lands)
- Fix config.md key-differences table: rate limits are in DynamicConfig,
  not StaticConfig

Mechanical fixes (Tier 1):
- overview.md: 'closes the QUIC stream' → 'closes the connection' (stale
  from pre-ADR-007 model)
- overview.md: OQ-04 entry updated from stale 'defer to implementation'
  to 'resolved: static at startup'
- mnemonic-derivation.md: remove duplicate helper functions block (incomplete
  first copy, complete second copy)
- ADR-003: add iroh (feature-gated) to alknet-core dependency list, added
  by ADR-010
- ADR-021: fix ambiguous 'W1 drift issue from the vault review' cross-reference
- ADR-022: rephrase FromCall 'leaf locally' to 'leaf in the local registry'
- ADR-017: add error_schemas to from_call mirror list and services/schema
  step (inconsistency with ADR-023)
- ADR-016: fix self-referential citation ('ADR-016 Assumption 5' → 'Assumption 5')
- Add ScopedOperationEnv::empty(), allows(), new() and
  CompositionAuthority::none(), new() impl blocks (referenced but undefined)
- Add call.completed clarification for non-subscription calls
- Add services/schema leading-slash normalization note
- Crate README ADR tables: add missing ADR-013 (call), ADR-015 (core),
  ADR-006 + ADR-010 (vault)
- Vault README: add consolidated 'Known Source Drift' table tracking all
  four drift items (OsRng, unwrap, CURRENT_KEY_VERSION, spawn bug) in one
  place, including the two previously missing from README

docs/architecture/decisions/004-auth-as-shared-core.md

@@ -12,6 +12,13 @@ The ALPN dispatch model simplifies this: every handler receives the same `AuthCo
 
 ## Decision
 
+> **Note**: The original text of this decision described the handler
+> "enriching or replacing" the `AuthContext`. This was superseded by
+> ADR-011, which made `AuthContext` immutable in `handle()` (passed as
+> `&AuthContext`). Handlers resolve identity into a local variable and
+> store it on `Connection` via `set_identity()`. The text below has been
+> updated to reflect the ADR-011 model.
+
 Authentication and identity resolution live in `alknet-core` as shared infrastructure. Each handler presents credentials differently, but all resolve through the same `IdentityProvider`:
 
 ```rust
@@ -36,7 +43,7 @@ Auth resolution is **hybrid** — the endpoint resolves what it can, and handler
 
 1. **Endpoint-level resolution** (before `handle()` is called): If the TLS handshake provides a client certificate, the endpoint resolves the fingerprint to an `Identity` and passes it in `AuthContext`. This is the case for SSH (where the key exchange happens at the protocol level, but the TLS layer may also provide information).
 
-2. **Handler-level resolution** (inside `handle()`): For protocols that carry credentials in application frames (AuthToken in the first call frame, Bearer header in HTTP), the handler extracts the credential from the stream and calls `IdentityProvider` to resolve it. The handler then enriches or replaces the partial `AuthContext` with the fully resolved `Identity`.
+2. **Handler-level resolution** (inside `handle()`): For protocols that carry credentials in application frames (AuthToken in the first call frame, Bearer header in HTTP), the handler extracts the credential from the stream and calls `IdentityProvider` to resolve it. The handler then resolves the `Identity` into a local variable and stores it on the `Connection` via `set_identity()` for observability — it does **not** mutate the `AuthContext` (which is passed as `&AuthContext`, an immutable reference — see ADR-011). The per-request identity (for ACL) is resolved separately by the `CallAdapter` at `call.requested` time.
 
 The `AuthContext` passed to `handle()` may be partial — containing only transport-level information if no TLS client certificate was provided. Handlers must not assume `AuthContext` contains a fully resolved `Identity`. Each handler knows its own credential extraction protocol and is responsible for completing authentication.