Handoff: reconcile docs and tooling with the corrections made this session

Session 2 reversed several of its own conclusions. The docs are append-only, so
a reader could land on a superseded section and act on it. This pass makes the
repo internally consistent.

Defects found and fixed in STATUS.md:
- claimed "Hybrid VQ with k=1024: no" as the answer to the linework question,
  directly contradicting FINDINGS 14, which rejected k=1024. Both profiles are
  k=256.
- malformed profile table (six column separators, five columns).
- next-steps list had two items numbered 3 and listed the full-disc survey
  twice.
- the disk-benchmark section still read CRITICAL-PATH with "if SCSI sustains
  >=800 KB/s, ship pixel-exact". That was written while the bandwidth figure
  was misread as 4 MB/s. At 4 Mbps pixel-exact needs 92-97% of the pipe and is
  not available, and the ring-buffer result means the design no longer hangs on
  the benchmark at all. Rewritten with what it IS still worth doing: confirming
  the 4 Mbps provenance, and confirming DMA is used rather than PIO.

FINDINGS now carries supersession blockquotes on 5, 8, 11, 17 and 18 pointing
at the sections that correct them. 18 is the dangerous one -- its peak-vs-
sustained test is reversed by 21 -- so it is marked DO NOT ACT ON THIS SECTION
while noting the per-frame data itself remains valid.

profile_gen.py had the same problem in code: it defaulted to the superseded
peak sizing and returned lam=25 where the docs say lam=10. The buffered test is
now the default and peak sizing is behind --size-for-peak as a bound only. A
tool that contradicts the findings is worse than no tool.

Also preserves the five measurement scripts that produced this session's
numbers as tools/analysis/05-09, following the session 1 precedent, and adds an
"explicitly abandoned -- do not re-propose" list to STATUS covering entropy
coding, k=1024 codebooks and flat 4x4 VQ.

Claude-Session: https://claude.ai/code/session_01194oWYW8DQXK1SZ2DnChW6

README.md

@@ -11,12 +11,18 @@ pushing ~22 minutes of Don Bluth animation through a 10MHz 68000.
   decision, and a section on measurement traps that produced three separate
   false results. Read §4 before trusting any pipeline number.
 - **`docs/STATUS.md`** — current state, working setup, blockers, next steps.
+  **Start here.** It also lists what has been explicitly abandoned, so old ideas
+  do not get re-proposed.
+- **`docs/BENCHMARK.md`** — how to measure the storage subsystem, and why a
+  bandwidth figure out of MAME would be meaningless.
 - **`docs/HARDWARE.md`** — X68000 GVRAM/CRTC reference.
 
 ## Layout
 ```
 docs/            findings, status, hardware reference
-tools/analysis/  frame-analysis scripts (01/02 marked BROKEN as regression refs)
+tools/analysis/  measurement scripts, numbered in the order they were written
+                 (01/02 marked BROKEN deliberately, kept as regression refs).
+                 Run from the repo root — they import from tools/encoder/.
 tools/bench/     MAME Lua injection harness + 68000 benchmark sources
 tools/vasm/      vasm m68k assembler (built from source)
 tools/encoder/   hybrid VQ encoder + DLX1 container writer (working)
@@ -31,12 +37,22 @@ python3 tools/encoder/extract.py 00020 /tmp/fr 12 crop
 python3 tools/encoder/encode.py  /tmp/fr out.dlx --profile sasi --preview p.png
 ```
 
-Two quality profiles ship from one codec and one decoder — `sasi` (45 KB/s) and
-`scsi` (120 KB/s) are two points on the same rate-distortion curve. The codec is
+Two quality profiles ship from one codec and one decoder — `sasi` (110 KB/s) and
+`scsi` (280 KB/s) are two points on the same rate-distortion curve. The codec is
 a Cinepak-style hybrid: each 4x4 block is coded as SKIP, one 4x4 codeword, four
 2x2 codewords, or RAW literal pixels, chosen per block by rate-distortion.
 
 The RAW escape means `lam=0` is pixel-exact against the palettised frame, so the
 quality knob spans lossless to heavily-compressed without changing the bitstream.
 
+Profiles are derived from a bandwidth figure, not chosen by eye:
+
+```
+python3 tools/encoder/profile_gen.py --bw-mbps 4 --name scsi
+```
+
+> **On reading `docs/FINDINGS.md`:** it is append-only and several later sections
+> overturn earlier ones. Superseded sections carry a blockquote at the top
+> pointing to the correction — heed those, especially 18 (reversed by 21).
+
 Source media (`DRAGONS_LAIR.iso`) and ROMs are gitignored — supply your own.