Add feedback loop: SQLite-backed rating system + MCP tools + GUI Training tab

New crate: soundgen-feedback
- FeedbackDB with SQLite (rusqlite, bundled)
- CRUD: add, update_rating, get_all, get_unrated, top_rated, delete
- search_similar: keyword-based similarity for few-shot reference
- export_jsonl: export rated examples for fine-tuning
- 9 tests

MCP server: 5 tools (was 3)
- generate_batch: generate multiple sounds by name, store in DB
- get_reference_sounds: search DB for highly-rated similar sounds
- render_sound: now returns reference examples from DB in response
- --db flag to specify feedback database path

GUI: Training tab
- Open/create feedback DB (file dialog)
- Generate batch dialog (enter names, output dir)
- Sound list with star rating (1-5), feedback text, play button
- Export dataset as JSONL
- Stats display (total/rated/avg rating)

OpenCode config updated with --db feedback.db path

Cargo.lock

@@ -1362,6 +1362,18 @@ dependencies = [
  "pin-project-lite",
 ]
 
+[[package]]
+name = "fallible-iterator"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2acce4a10f12dc2fb14a218589d4f1f62ef011b2d0cc4b3cb1bba8e94da14649"
+
+[[package]]
+name = "fallible-streaming-iterator"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7360491ce676a36bf9bb3c56c1aa791658183a54d2744120f27285738d90465a"
+
 [[package]]
 name = "fastrand"
 version = "1.9.0"
@@ -1711,6 +1723,15 @@ dependencies = [
  "bitflags 2.13.0",
 ]
 
+[[package]]
+name = "hashbrown"
+version = "0.14.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5274423e17b7c9fc20b6e7e208532f9b19825d82dfd615708b70edd83df41f1"
+dependencies = [
+ "ahash",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.15.5"
@@ -1726,6 +1747,15 @@ version = "0.17.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed5909b6e89a2db4456e54cd5f673791d7eca6732202bbf2a9cc504fe2f9b84a"
 
+[[package]]
+name = "hashlink"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ba4ff7128dee98c7dc9794b6a411377e1404dba1c97deb8d1a55297bd25d8af"
+dependencies = [
+ "hashbrown 0.14.5",
+]
+
 [[package]]
 name = "hassle-rs"
 version = "0.11.0"
@@ -2105,6 +2135,17 @@ dependencies = [
  "redox_syscall 0.8.1",
 ]
 
+[[package]]
+name = "libsqlite3-sys"
+version = "0.28.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c10584274047cb335c23d3e61bcef8e323adae7c5c8c760540f73610177fc3f"
+dependencies = [
+ "cc",
+ "pkg-config",
+ "vcpkg",
+]
+
 [[package]]
 name = "linux-raw-sys"
 version = "0.3.8"
@@ -2973,6 +3014,20 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "19b30a45b0cd0bcca8037f3d0dc3421eaf95327a17cad11964fb8179b4fc4832"
 
+[[package]]
+name = "rusqlite"
+version = "0.31.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b838eba278d213a8beaf485bd313fd580ca4505a00d5871caeb1457c55322cae"
+dependencies = [
+ "bitflags 2.13.0",
+ "fallible-iterator",
+ "fallible-streaming-iterator",
+ "hashlink",
+ "libsqlite3-sys",
+ "smallvec",
+]
+
 [[package]]
 name = "rustc-hash"
 version = "1.1.0"
@@ -3313,6 +3368,18 @@ dependencies = [
  "serde_json",
 ]
 
+[[package]]
+name = "soundgen-feedback"
+version = "0.1.0"
+dependencies = [
+ "rusqlite",
+ "serde",
+ "serde_json",
+ "soundgen-core",
+ "soundgen-fmt",
+ "uuid",
+]
+
 [[package]]
 name = "soundgen-fmt"
 version = "0.1.0"
@@ -3332,8 +3399,10 @@ dependencies = [
  "eframe",
  "egui",
  "egui-file-dialog",
+ "hound",
  "serde_json",
  "soundgen-core",
+ "soundgen-feedback",
  "soundgen-fmt",
  "soundgen-io",
  "soundgen-seq",
@@ -3356,6 +3425,7 @@ dependencies = [
  "serde",
  "serde_json",
  "soundgen-core",
+ "soundgen-feedback",
  "soundgen-fmt",
  "soundgen-io",
 ]
@@ -3711,6 +3781,23 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 
+[[package]]
+name = "uuid"
+version = "1.23.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "144d6b123cef80b301b8f72a9e2ca4370ddec21950d0a103dd22c437006d2db7"
+dependencies = [
+ "getrandom 0.4.3",
+ "js-sys",
+ "wasm-bindgen",
+]
+
+[[package]]
+name = "vcpkg"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "accd4ea62f7bb7a82fe23066fb0957d48ef677f6eeb8215f372f52e48bb32426"
+
 [[package]]
 name = "version_check"
 version = "0.9.5"