3do: SVG-derived logo, layout fixes, README + build script cleanup.

Logo: regenerate from branding/logo_solid_black.svg via rsvg-convert
at 76x64 (matches the SVG's 1.177:1 aspect natively). Removes the
runtime HDX stretch hack -- the source PNG now has the right
proportions and the cel renders 1:1.

Layout fixes on the device row:
  - K: column shifted from x=108 to x=128 to clear the ID column
    (which ends at x=112 after the move to x=96).
  - Keyboard terminal-input row starts at x=40, aligned with the
    Type column. Buffer cap reduced to 33 chars to fit the narrower
    available width after the prompt.

README rewritten: dropped the wrong "chipped console" line (3DO
boots CD-Rs natively), trimmed the toolchain history, condensed the
device-class explanation to one table.

build_docker.sh: dropped the cport*.rom case-rename loop (OperaFS
is case-insensitive AND we static-link the driverlets, so disc-load
filename case never matters) along with the rest of the AI-narrative
comments. Same behaviour, ~30% fewer lines.

Author: RobertDaleSmith

3do/README.md

@@ -1,115 +1,70 @@
 # Joypad Tester — 3DO
 
-3DO Opera (Panasonic FZ-1 / FZ-10, GoldStar GDO, Sanyo TRY, etc.)
-build of the [Joypad Tester](../README.md). Reads the 3DO control
-pad daisy-chain and renders the live button state on screen.
+3DO build of the [Joypad Tester](../README.md). Talks directly to the
+Portfolio event broker and renders the live state of every PBUS
+device on the daisy chain.
 
-## What it tests
+## What it shows
 
-The active 3DO control pad's full 32-bit `DoControlPad` bitfield,
-shown as raw hex plus a per-button held-or-not grid:
+One row per detected pod. Layout:
 
 ```
 Joypad Tester - 3DO
 ===================
 
-P1 raw: 0x00000000
-P2 raw: 0x00000000
-
-P1 buttons:
-.       .
-.       .
-.       .
-.       .
-.       .
-.
+P  TYPE     ID
+1  PAD      80    U . . R . A B C . P . R
+2  MOUSE    49    X-032 Y+069  L . R
+3  STICK    01    . . L . F A . . . P . .
+                  H+000 V-018 D+002
+4  GUN      4D    C 28800  L1  T
+5  ARCADE   C0    .  S1  .  S2  Sv
+6  KEYB     4B    K:02  1C 23 -- --
+                  > hello world_
 ```
 
-| Source | Detected as |
-|--------|-------------|
-| 3DO control pad (D-pad, A/B/C, Start, Stop, L/R shift) | `DoControlPad` slot 1 / slot 2 |
-| 3DO mouse / lightgun / arcade panel | not yet wired (uses different SDK calls) |
-
-Buttons rendered: Up, Down, Left, Right, A, B, C, Start, Stop, L (Left
-Shift), R (Right Shift). "Stop" is the X button on the original 3DO
-pad — its symbol is the eject-style square.
-
-## trapexit/3do-devkit toolchain
-
-3DO homebrew is built with the Norcroft ARM C/C++ compilers (originally
-1990s ARM Ltd / Acorn) bundled in
-[trapexit/3do-devkit](https://github.com/trapexit/3do-devkit). The
-devkit also ships 3DO Portfolio SDK headers + a small modern C++
-helper layer (`BasicDisplay`, `abort_err`, etc.) that we link
-against unmodified. We pin to a specific devkit commit
-(`e0845bc4` at v0.1.0) inside [`buildtools/Dockerfile`](buildtools/Dockerfile);
-bumping it = rebuilding the image.
+| Class      | PBUS ID(s)  | Decoded fields                                |
+|------------|-------------|-----------------------------------------------|
+| `PAD`      | 0x80 / 0xA0 | D-pad, A/B/C, X, P (Start), L/R Shift         |
+| `MOUSE`    | 0x49        | X / Y delta, L / M / R                        |
+| `STICK`    | 0x01        | H / V / D analog, Fire/A/B/C/X/P/Shifts + hat |
+| `GUN`      | 0x4D        | timing counter, line pulse, trigger           |
+| `ARCADE`   | 0xC0        | P1/P2 Coin / Start, Service                   |
+| `KEYB`     | 0x02 / 0x4B | 256-bit matrix + terminal-style typed text    |
+| any other  | `0xNN`      | shown by raw class byte                       |
 
-The compilers are 32-bit x86 binaries (Linux only) — and one
-post-compile step (`3doiso`) is a Windows binary the devkit runs via
-Wine. The Docker image bakes both: `libc6-i386` for the 32-bit
-dynamic loader, `wine32` for the iso composer. On Apple Silicon or
-any non-x86 host, the container runs under `--platform=linux/amd64`.
+After 30 s of no input → bouncing-logo screensaver. Any input wakes.
 
 ## Build
 
-The toolchain is Docker-only:
+Docker-only:
 
 ```
-./build_docker.sh                # build (first run also builds image)
-./build_docker.sh clean          # nuke build/
-./build_docker.sh rebuild-image  # force toolchain image rebuild
+./build_docker.sh                # build
+./build_docker.sh clean
+./build_docker.sh rebuild-image
 ```
 
-`build/joypad-tester.iso` is the in-tree output. CI builds on every
-push to `main` (see
-[`.github/workflows/verify-build.yml`](../.github/workflows/verify-build.yml)).
-
-## Loading on hardware
-
-### 3DO emulator (Opera / Phoenix / RetroArch's Opera core)
-
-Drop `joypad_tester_v<ver>.iso` onto the emulator. Opera-based
-cores require a 3DO BIOS dump in their `system/` directory
-(`panafz1.bin` / `panafz10.bin` / `goldstar.bin` / `sanyotry.bin`).
-
-### Real 3DO hardware
-
-Burn the `.iso` to CD-R (700 MB blank, ISO mode — 3DO Opera
-filesystem is iso9660-compatible enough that standard burning tools
-handle it). Boot on a chipped console; unmodified retail consoles
-won't boot homebrew CDs.
-
-ODE / SD-loader options like the
-[Plextor / Polymega-replacement chips](https://3dodev.com/) are
-the contemporary path; check 3dodev.com for current hardware notes.
-
-## Releases
-
-Tagged as `3do-v<semver>` from the repo root — see
-[`3do/CHANGELOG.md`](CHANGELOG.md) for per-version notes. The release
-workflow attaches `joypad_tester_v<semver>_3do.iso` to each GitHub
-Release.
-
-## Origin / credits
-
-Built on Antonio SJ Musumeci's
-[3do-devkit](https://github.com/trapexit/3do-devkit) (ISC) — see
-[`LICENSE.md`](LICENSE.md). The Joypad Tester source
-(`src/main.cpp`) is original; `BasicDisplay` + `abort_err` come
-verbatim from the devkit and link in as part of the standard
-homebrew build.
-
-3DO Portfolio SDK headers / libraries shipped within the devkit are
-originally copyrighted by The 3DO Company and widely redistributed
-in the 3DO homebrew scene.
-
-Charles Doty (RasterSoft) wrote the original
-**3DO Controller Test Multi** (2016) — released "free of any licences,
-credit would be appreciated but not required". Distributed in the
-homebrew scene by Aer Fixus. Source is available on
-[3dodev.com](https://3dodev.com/software/homebrew/console_tools).
-Their 8-pad polling loop + Sprite/CEL rendering modules are the
-reference shape for our v0.2 multi-controller + screensaver work
-(see `.dev/docs/3do_roadmap.md`). v0.1.0 is a from-scratch bring-up
-against the modern trapexit devkit's `BasicDisplay` helper.
+Compiles `main.cpp` against
+[trapexit/3do-devkit](https://github.com/trapexit/3do-devkit), then
+rebuilds the event broker daemon from
+[trapexit/portfolio_os](https://github.com/trapexit/portfolio_os) with
+every driverlet (pad, mouse, stick, lightgun, glasses, keyboard, plus
+a local `SillyPadDriver.c` for 0xC0) static-linked in. Output:
+`build/joypad-tester.iso`.
+
+## Loading
+
+- **CD-R** — burn the ISO, boot it. No modchip needed.
+- **ODE** — drop the ISO on the SD.
+- **Emulator** — RetroArch's Opera core / standalone Opera / Phoenix.
+  Requires a 3DO BIOS in the emulator's `system/`.
+
+## Credits
+
+- Build infra: [trapexit/3do-devkit](https://github.com/trapexit/3do-devkit) (ISC).
+- Driverlets: [trapexit/portfolio_os](https://github.com/trapexit/portfolio_os), with the keyboard one finished by us (PR open).
+- `SillyPadDriver.c`: new, written from the PBUS spec + the
+  [SNES23DO](https://github.com/SNES23DO/SNES23DO) firmware reference
+  (Orbatak baked its 0xC0 driver into its game binary, no
+  redistributable `CPORTC0.ROM` ever shipped).