Release v0.3.0: compiled forms — ReadPlan, owned BastDoc, LeafMeta, ValidationPlan, fingerprinting

Public API bump 0.2.0 -> 0.3.0 (the 030-compiled-forms plan is now
fully implemented; all eight phases landed).

- Cargo.toml: version 0.3.0. lib.rs re-exports complete (ReadPlan +
  sub-types, LeafMeta, OffsetEntry, ValidationPlan + sub-types).
- ADR-007 "Cost" rewritten to the Arc<ReadPlan> cost (15.7 ns) with
  the 0.2.0 "re-parse on demand" framing as a historical note
  (review #004 L2, the last loose end from that review).
- ADR-011/012 status blocks flipped to implemented; architecture
  README ADR table rows updated; layout-engine.md rewritten for the
  0.3.0 surface (engine-factory reader construction, OffsetMap
  OffsetEntry/LeafMeta/fingerprint section, owned BastDoc compute
  signature); SequentialReader module doc points at the engine
  factory. Reviews #004 and #005 flipped to closed.
- Bench re-run (alktty wire_vs_bast, 0.3.0 tree): read p64 98
  ns/chunk (parity with phase 2; hand-rolled 5.7 us/stream),
  layout_build 180 ns (was ~1.2 us — the phase-4 owned-doc cache
  removed the per-build re-parse, ~7x), sequential_reader_new 15.7
  ns, write p64 -3%, engine_compile unchanged (meta-schema
  validation dominates). No dedicated validate_bytes-stream bench:
  the phase-7 spot check (~0.2 us plan-validate vs ~0.6 us
  compile-per-call) stands; a dedicated bench is a follow-up if
  alkcall profiling motivates it.
- Downstream: alktty compiles against the path dep unchanged; alkcall
  has no dependency yet.

Verification (full block, all green): 474 tests; clippy -D warnings
clean; cargo doc zero warnings; wasm32 release build green; cargo
publish --dry-run clean at 0.3.0.

docs/architecture/README.md

@@ -45,8 +45,8 @@ format definition; the engine is generic.
 | [008](decisions/008-reject-tunion-in-aligned-mode.md) | Reject TUnion in Aligned Mode for v1 | Unions are the protocol pattern; aligned-mode union semantics were broken |
 | [009](decisions/009-builder-api.md) | Builder API for Schema Construction | Fluent Rust API producing `serde_json::Value`; covers BAST kinds + standard JSON Schema; resolves OQ-003. *Output format amended to BAST / standard JSON Schema by ADR-BAST.* |
 | [010](decisions/010-generalized-validation-validate-bytes.md) | Generalized Validation — `validate_bytes` on `AlkTypeEngine` | Single-call binary-buffer validation; materialize `Value` from bytes, then validate. *Validation step amended to the BAST-native validator by ADR-VAL-SPLIT.* |
-| [011](decisions/011-compiled-read-plan-for-packed-mode.md) | Compiled Read Plan for Packed Mode | `ReadPlan` — the packed read-side compiled form, symmetric to `OffsetMap` (aligned) and `PackedLayout` (packed write). Closes review #004's 400x read-path gap; retires ADR-007's "re-parse on demand" framing. *Accepted.* |
-| [012](decisions/012-plan-fingerprinting-and-m1-closure.md) | Plan Fingerprinting, ValidationPlan, and Closing the Deferred M1 Sites in 0.3.0 | `ReadPlan`/`OffsetMap`/`ValidationPlan` `Hash + Eq` + `fingerprint()`; owned `BastDoc` (lifetime removal); `OffsetMap` carries `LeafMeta` to close the aligned-side M1 sites; `ValidationPlan` retires the interpretive `bast_validation` walk (review #005 M3 reversed the original deferral). Bundles with ADR-011 into one 0.3.0 breaking release. *Accepted — §3a shape implemented in `src/validation_plan.rs`.* |
+| [011](decisions/011-compiled-read-plan-for-packed-mode.md) | Compiled Read Plan for Packed Mode | `ReadPlan` — the packed read-side compiled form, symmetric to `OffsetMap` (aligned) and `PackedLayout` (packed write). Closes review #004's 400x read-path gap; retires ADR-007's "re-parse on demand" framing. *Accepted — implemented in 0.3.0 (phases 1–2).* |
+| [012](decisions/012-plan-fingerprinting-and-m1-closure.md) | Plan Fingerprinting, ValidationPlan, and Closing the Deferred M1 Sites in 0.3.0 | `ReadPlan`/`OffsetMap`/`ValidationPlan` `Hash + Eq` + `fingerprint()`; owned `BastDoc` (lifetime removal); `OffsetMap` carries `LeafMeta` to close the aligned-side M1 sites; `ValidationPlan` retires the interpretive `bast_validation` walk (review #005 M3 reversed the original deferral). Bundles with ADR-011 into one 0.3.0 breaking release. *Accepted — fully implemented in 0.3.0 (fingerprinting, owned `BastDoc`, `LeafMeta`, `ValidationPlan`).* |
 
 ## Relevant Open Questions