feat(pii): NER tier engine — privacy-filter.cpp backend + NER-centric PII filter (#10360)

Squashed feat/pii-ner-tier-engine rebased onto master (was 45 commits; see
backup/pii-ner-tier-engine-prerebase). Net change:

- privacy-filter.cpp: standalone GGML engine for the openai-privacy-filter
  PII/NER token classifier, wired as a LocalAI gRPC backend (CPU/CUDA/Vulkan).
  TokenClassify moves off the patched llama.cpp path onto this backend.
- PII filter reworked to be NER-centric (encoder/NER detection tier scanning
  whole conversations as one document), with a recreated bounded restricted-
  regex secret-matching pattern detector tier alongside it (per-model
  pii_detection.builtins / .patterns + core/services/routing/piipattern).
- Detection labelled by source (ner vs pattern); backend trace / confidence /
  debug observability; analyze/redact exposed as a synchronous API.
- Instance-wide default detector policy + per-usecase default-on; request
  filtering extended to completions, embeddings, edits & Ollama.
- React UI: NER-centric PII editor, detector-models table, pattern/builtins
  editor, middleware default-policy UI.
- Gallery: privacy-filter-multilingual token-classify model + NER install
  filter; token_classify known_usecase; batch sized to context for NER models.
  privacy-filter backend registered in the backend gallery (cpu/vulkan/cuda-13
  meta + image entries with a capabilities map) matching its CI matrix jobs,
  and an /import-model auto-detect importer (PrivacyFilterImporter, narrow
  privacy-filter GGUF detection) replacing the prior pref-only registration.

Reconciled against master's independent evolution:

- Dropped master's PIIPatternOverrides feature (global-pattern runtime
  overrides + /api/pii/patterns API + runtime_settings.json persistence). The
  per-model NER + pattern-detector design supersedes it; it was built on the
  global redactor pattern set this branch replaced.
- Reverted the llama.cpp Score carry-patch (0006-server-task-type-score):
  removed the patch and restored master's grpc-server.cpp Score RPC (direct
  llama_decode, slot-loop bypass) and LLAMA_VERSION pin, plus master's
  model_config validation forbidding score + chat/completion/embeddings on
  llama-cpp. token_classify is unaffected (it runs on the privacy-filter
  backend, not llama-cpp).

Assisted-by: Claude:claude-opus-4-8 [Claude Code]

Signed-off-by: Richard Palethorpe <io@richiejp.com>

core/http/auth/features.go

@@ -123,6 +123,10 @@ var RouteFeatureRegistry = []RouteFeature{
 	{"GET", "/api/fine-tuning/jobs/:id/download", FeatureFineTuning},
 	{"POST", "/api/fine-tuning/datasets", FeatureFineTuning},
 
+	// PII analyze/redact service (the events log stays admin-gated in-handler)
+	{"POST", "/api/pii/analyze", FeaturePIIFilter},
+	{"POST", "/api/pii/redact", FeaturePIIFilter},
+
 	// Quantization
 	{"POST", "/api/quantization/jobs", FeatureQuantization},
 	{"GET", "/api/quantization/jobs", FeatureQuantization},
@@ -181,5 +185,6 @@ func APIFeatureMetas() []FeatureMeta {
 		{FeatureFaceRecognition, "Face Recognition", true},
 		{FeatureVoiceRecognition, "Voice Recognition", true},
 		{FeatureAudioTransform, "Audio Transform", true},
+		{FeaturePIIFilter, "PII Analyze / Redact", true},
 	}
 }

core/http/auth/permissions.go

@@ -56,6 +56,10 @@ const (
 	FeatureFaceRecognition    = "face_recognition"
 	FeatureVoiceRecognition   = "voice_recognition"
 	FeatureAudioTransform     = "audio_transform"
+	// FeaturePIIFilter gates the synchronous PII analyze/redact service
+	// (POST /api/pii/{analyze,redact}). Default ON like the other API
+	// features; the admin-only events log is gated separately in-handler.
+	FeaturePIIFilter = "pii_filter"
 )
 
 // AgentFeatures lists agent-related features (default OFF).
@@ -71,6 +75,7 @@ var APIFeatures = []string{
 	FeatureVAD, FeatureDetection, FeatureVideo, FeatureEmbeddings, FeatureSound,
 	FeatureRealtime, FeatureRerank, FeatureTokenize, FeatureMCP, FeatureStores,
 	FeatureFaceRecognition, FeatureVoiceRecognition, FeatureAudioTransform,
+	FeaturePIIFilter,
 }
 
 // AllFeatures lists all known features (used by UI and validation).