fix: plugin no longer vanishes after Claude Code updates

Root cause: plugin registered as directory source in known_marketplaces.json,
which gets wiped on CLI updates. Now registers in extraKnownMarketplaces
(settings.json) as a GitHub source — same mechanism caveman/context-mode use.

Binaries install to ~/.claude-mnemonic/bin/ instead of the Claude-managed
plugins directory. Thin wrapper scripts in the repo let the marketplace
clone find them. Nothing gets cleaned up when Claude refreshes its cache.

Also fixed along the way:
- ONNX Runtime 1.24.3 → 1.26.0 (API v25 mismatch broke all embedding tests)
- Vector client leaked on DB reinit, processQueue had a race on sessionManager
- reloadConfig called os.Exit(0) bypassing graceful shutdown
- Removed dead QueryRowWithTimeout that leaked contexts
- Added tests for graph/watcher/maintenance/update (all were at 0%)

go.mod

@@ -6,16 +6,16 @@ replace github.com/sugarme/tokenizer => github.com/clems4ever/tokenizer v0.0.0-2
 
 require (
 	github.com/asg017/sqlite-vec-go-bindings v0.1.6
-	github.com/fsnotify/fsnotify v1.9.0
-	github.com/go-chi/chi/v5 v5.2.5
+	github.com/fsnotify/fsnotify v1.10.1
+	github.com/go-chi/chi/v5 v5.3.0
 	github.com/go-gormigrate/gormigrate/v2 v2.1.5
 	github.com/goccy/go-json v0.10.6
-	github.com/mattn/go-sqlite3 v1.14.42
+	github.com/mattn/go-sqlite3 v1.14.44
 	github.com/rs/zerolog v1.35.1
 	github.com/smacker/go-tree-sitter v0.0.0-20240827094217-dd81d9e9be82
 	github.com/stretchr/testify v1.11.1
 	github.com/sugarme/tokenizer v0.3.0
-	github.com/yalue/onnxruntime_go v1.27.0
+	github.com/yalue/onnxruntime_go v1.30.1
 	golang.org/x/sync v0.20.0
 	gorm.io/driver/sqlite v1.6.0
 	gorm.io/gorm v1.31.1
@@ -27,14 +27,14 @@ require (
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
 	github.com/mattn/go-colorable v0.1.14 // indirect
-	github.com/mattn/go-isatty v0.0.21 // indirect
+	github.com/mattn/go-isatty v0.0.22 // indirect
 	github.com/mitchellh/colorstring v0.0.0-20190213212951-d06e56a500db // indirect
 	github.com/patrickmn/go-cache v2.1.0+incompatible // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/rivo/uniseg v0.4.7 // indirect
 	github.com/schollz/progressbar/v2 v2.15.0 // indirect
 	github.com/sugarme/regexpset v0.0.0-20200920021344-4d4ec8eaf93c // indirect
-	golang.org/x/sys v0.43.0 // indirect
-	golang.org/x/text v0.36.0 // indirect
+	golang.org/x/sys v0.45.0 // indirect
+	golang.org/x/text v0.37.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )