fix: real preset data for all VST2/VST3 plugins, template system with ground-truth registry

- Extracted preset data from all_plugins_v2.rpp for 14 previously broken plugins
- Fixed PLUGIN_REGISTRY entries: Kontakt 7, Gullfoss, ValhallaDelay, VC 160/76, The Glue
- Template parser falls back to PLUGIN_PRESETS when source RPP has fake data
- Substitute Transient Master (not installed) with FabFilter Pro-C 2
- All 25 plugins now load correctly in REAPER
- Added template generator scripts and ground truth references
- Cleaned up temp/debug files from output/

sdd/fix-drum-sample-paths/design.md

@@ -0,0 +1,70 @@
+# Design: `fix-drum-sample-paths`
+
+**Type**: bugfix  
+**Bug**: Drum samples silent — `samples_dir/output/samples/` paths point to nonexistent directory  
+**Root cause**: `compose_full_track.py` passes bare filenames to skeleton, which joins them with `samples_dir` expecting `output/samples/`. But `pick()` returns absolute paths from the sample library. The mismatch makes FL Studio look in the wrong place.
+
+---
+
+## Changes
+
+### 1. `scripts/compose_full_track.py` — lines 201–210
+
+**Problem**: `samples` dict receives bare filenames (`ch10_perc`, etc.) but skeleton needs absolute paths.
+
+**Fix**: Change the `samples` dict to use the `path*` variables returned by `pick()`, which are absolute paths.
+
+```python
+# Before (broken)
+samples = {
+    "channel10": ch10_perc,   # bare filename e.g. "perc_loop.wav"
+    ...
+}
+
+# After (fixed)
+samples = {
+    "channel10": path10,      # absolute path e.g. "C:\Users\...\library\perc_loop.wav"
+    ...
+}
+```
+
+The `path*` variables already exist and hold `m.get("original_path")` from `pick()`. No other code needs changing — the samples dict key→channel mapping is already correct.
+
+---
+
+### 2. `src/flp_builder/skeleton.py` — `_patch_sample_path()` around line 361
+
+**Problem**: `_patch_sample_path()` always joins `wav_name` with `self.samples_dir`, which breaks when `wav_name` is already an absolute path (as it now is after fix #1).
+
+**Fix**: Add an absolute-path guard before joining:
+
+```python
+# In _patch_sample_path(), replace line 361:
+# Before
+full_path = os.path.join(self.samples_dir, wav_name)
+
+# After
+if Path(wav_name).is_absolute():
+    full_path = wav_name
+else:
+    full_path = os.path.join(self.samples_dir, wav_name)
+```
+
+This preserves existing behavior for relative paths (used elsewhere) while correctly handling the absolute paths now being passed.
+
+---
+
+## Files affected
+
+| File | Lines | Change |
+|------|-------|--------|
+| `scripts/compose_full_track.py` | 201–210 | Use `path*` vars instead of `ch*_var` vars |
+| `src/flp_builder/skeleton.py` | 361 | Add `is_absolute()` guard |
+
+---
+
+## Verification
+
+- **Before fix**: `compose_full_track.py` prints `ch10: some_file.wav` (bare filename)
+- **After fix**: `compose_full_track.py` prints full paths, skeleton detects them and skips join
+- Run `python scripts/compose_full_track.py` — FLP should load drum samples correctly