testhost: trim resolved coverage-gap note in TODO.md

The chunk-advertisement misdiagnosis is already fully disproved and
documented in tests/README.md's "corrected finding" section; condense the
TODO.md entry to a one-line resolved note instead of duplicating the full
narrative, keeping only the genuinely still-open question (why specific
old external .fxp sample files fail to apply).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011dhtwRLARk4eiPngcQykLJ

tools/testhost/TODO.md

@@ -59,26 +59,18 @@ verified (PR https://git.jayfield.org/jens/JaySynth/pulls/1).
 - [ ] **Bundled sample `.fxp` files under `extras/sounds/` silently have no
   effect when loaded via `--patch`** (confirmed by diffing `--printParams`
   output with and without `--patch` - zero parameters differ), even though
-  loading doesn't crash. **Correction**: an earlier version of this entry
-  claimed this was because JaySynth's compiled VST2 wrapper never sets
-  `effFlagsProgramChunks`, so JUCE's host-side `usesChunks()` would see
-  false and skip the chunk mechanism entirely. That diagnosis was wrong -
-  disproved directly: `--saveBank`/`--savePatch` (the exact same generic
-  `AudioProcessor::getStateInformation` path) produce real `FBCh`/`FPCh`-
-  magic, GZIP-compressed-XML files (confirmed via hex dump and by feeding
-  the raw inner chunk bytes straight to `effSetChunk` via the new
-  `Vst2RawChunk` bypass, added specifically to rule this out - still no
-  effect). So `usesChunks()` genuinely is true, and `test_chunk_roundtrip`
-  in `tests/run_tests.sh` proves the real `bankEncodeXml`/`bankDecodeXml`
-  path round-trips correctly for files this build produces. The actual
-  cause of the *external* sample files failing is still unidentified -
-  most likely those specific (10+ year old) files use a compression or
-  XML-schema shape that `JaySynthAudioProcessor::setCurrentProgramState-
-  Information`/`getXmlFromBinary` no longer parses, not a host/plugin
-  capability mismatch. Not one of the tracked repo-root `TODO.md` findings.
-  Worth a closer look at some point (e.g. hex-diff one of these files'
-  decompressed XML against what this build produces), but not chased
-  further here. See `tests/README.md`'s "corrected finding" note.
+  loading doesn't crash. Resolved: this is *not* a host/plugin capability
+  mismatch - `usesChunks()` is genuinely true and `test_chunk_roundtrip` in
+  `tests/run_tests.sh` proves the real `bankEncodeXml`/`bankDecodeXml` chunk
+  path round-trips correctly for files this build produces (see
+  `tests/README.md`'s "corrected finding" note for the full disproof). What
+  remains open is narrower: why these specific (10+ year old) *external*
+  sample files fail to apply - most likely a compression or XML-schema
+  shape that `JaySynthAudioProcessor::setCurrentProgramStateInformation`/
+  `getXmlFromBinary` no longer parses. Not one of the tracked repo-root
+  `TODO.md` findings; worth a closer look at some point (hex-diff one of
+  these files' decompressed XML against what this build produces), but not
+  chased further here.
 - [ ] **DPF-based plugins print a non-fatal assertion on load.** All three
   Zam*-vst.so plugins tested (built with the DISTRHO Plugin Framework) print
   `assertion failure: "fIsActive" in .../DistrhoPluginInternal.hpp` during