Polish for merge to master

- Fix double-close in decode.ts: use try/finally per resource so cleanup
  doesn't run twice on partial failures.
- Drop unused deps (implode-decoder, stream-buffers, @types/stream-buffers)
  and orphan BufferFirstDifference.ts left over from the old decoder path.
- Set process.exitCode on error so failures actually fail.
- Expand README with the container layout and CLI options.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: cinderblock

README.md

@@ -1,8 +1,24 @@
 # Electronics Workbench Decoder (and Encoder?)
 
+Decompresses National Instruments Electronics Workbench / Multisim / Ultiboard
+project files (`.ewprj`, `.ms14`) into their underlying XML.
+
+The container is a small header (`CompressedElectronicsWorkbenchXML` or
+`MSMCompressedElectronicsWorkbenchXML`) followed by a 64-bit total decompressed
+length, then a sequence of `(decompressed_length: u32, compressed_length: u32, pkware_implode_block)` sections. Compression is PKWare DCL Implode (ASCII,
+large dictionary).
+
+For each input file, a `<filename>.xml` is written next to the input.
+
 ## Development
 
 ```bash
 npm i
-npm run dev -- --verbose ../path-to-file.ewprj ../path-to-file2.ewprj
+npm run dev -- --verbose ./samples/Temp.ewprj ./samples/Design1.ms14
 ```
+
+CLI options:
+
+- `-v`, `--verbose` — log per-section progress
+- `-c`, `--concurrent` — decode multiple files in parallel
+- positional args — files to decode