docs: complete 0.13.6 docs sweep (architecture, api-design, disc-to-rip, README)

Follow-up to the rip-recovery + drive-access updates: aligns the
remaining docs with the v0.13.6 single-shot read model and the
three-layer recovery architecture.

- architecture.md: module map says single-shot read; new paragraph on
  layered recovery with postmortem pointer.
- api-design.md: EventKind enum example expanded; emission notes
  document that BytesRead now fires from DiscStream::fill_extents and
  Retry/SectorRecovered are no longer emitted in 0.13.6+.
- disc-to-rip.md: Step 10 of the pipeline diagram + module table
  reflect single-shot read.
- docs/README.md: added rip-recovery.md to the TOC.

docs/architecture.md

@@ -41,7 +41,7 @@ AACS keys are derived internally, and all SCSI communication is handled in-proce
 libfreemkv (lib.rs)
 │
 ├── Drive Access
-│   ├── drive         Drive — open, identify, init, unlock, read (with recovery)
+│   ├── drive         Drive — open, identify, init, unlock, single-shot read
 │   ├── scsi          ScsiTransport trait + platform backends (sg async, IOKit, SPTI)
 │   ├── platform/     Platform trait — per-chipset command handlers
 │   │   └── mt1959    MediaTek MT1959 driver (LG, ASUS, HP)
@@ -93,10 +93,17 @@ Drive::open(Path::new("/dev/sg4"))
 After open:
 - `init()` -- unlock + firmware upload + speed calibration
 - `probe_disc()` -- probe disc surface for optimal speeds
-- `read(lba, count, buf)` -- single read method with built-in error recovery
+- `read(lba, count, buf, recovery)` -- single-shot read; `recovery` only selects the per-CDB timeout (1.5 s vs. 30 s)
 - `wait_ready()` -- wait for disc insertion
 - `eject()` -- eject tray
 
+Recovery is layered above `Drive::read`, not inside it. Layer 1
+(`Disc::patch`) handles bad-range retry by replaying the ddrescue mapfile.
+Layer 3 (`DiscStream::fill_extents` adaptive batch sizer) handles in-loop
+request-size adaptation. Inline recovery (gentle retry → SCSI reset → retry)
+was removed in 0.13.6 — see [`rip-recovery.md`](rip-recovery.md) and
+`freemkv-private/postmortems/2026-04-25-stop-wedge-and-zero-kbs.md`.
+
 ---
 
 ## Disc Scanning Flow