fix(pii): post-merge review fixes + live NER e2e for the privacy-filter tier (#10401)

* fix(pii): post-merge review fixes + live NER e2e for the privacy-filter tier

Follow-up to the NER tier engine (#10360), already on master. This carries
only the incremental review fixes and tests that postdate that merge — the
feature itself is not re-introduced.

Review fixes:
- openai_completion.go: remove the dead `elem >= 0` conjunct in applyAnyText
  (the `elem < 0` guard above already returns).
- application.go: collapse ResolvePIIPolicy's inline re-implementation of
  PIIIsEnabled to a single cfg.PIIIsEnabled() call (sole source of the
  "explicit pii.enabled wins, else cloud-proxy default" rule) and return true
  past the !enabled guard where it is provable.
- pattern.go: hoist the triple `appConfig != nil && EnableTracing` check in
  patternDetector.Detect into one local.
- grammar.go: MaxQuantifier was 4096, but Go's regexp/syntax rejects repeat
  bounds above 1000 at Parse time, so walk()'s {n,m} guard could never fire —
  dead code shadowed by the parser. Lower it to 512 so a bound in (512,1000]
  is rejected here with an actionable error; >1000 still fails closed via
  Parse. Specs pin the relationship so the guard can't silently revert.
- PatternListEditor.jsx: clamp a directly-typed negative min_len to >=0 and
  force the DOM value back when clamping (min={0} only constrained the spinner,
  so a negative reached saved config and silently disabled the length filter).

Tests:
- piipattern_test.go: MaxQuantifier guard specs (must stay live, not dead).
- model-config.spec.js: assert the min_len clamp, and that entity_actions
  collapses a duplicate group to a single row (map semantics; regression guard
  against emitting an array that drops a row on save).
- tests/e2e-backends: token_classify capability driving the TokenClassify gRPC
  RPC against the backend image, asserting byte-correct, UTF-8 rune-aligned
  spans (entity.Text == text[start:end]) at threshold 0. Verified on CPU via
  `make test-extra-backend-privacy-filter` (3/3 specs).
- Makefile: test-extra-backend-privacy-filter wrapper.
- tests/e2e: e2e_pii_ner_test.go drives /api/pii/analyze + /api/pii/redact
  (mask + block) through the full HTTP -> detector -> redactor path; gated on
  PII_NER_MODEL_GGUF so the default suite is unaffected.
- .github/workflows/tests-pii-ner-e2e.yml: path-filtered / nightly CI job
  running the container harness on CPU.

Assisted-by: Claude:claude-opus-4-8 [Claude Code]
Signed-off-by: Richard Palethorpe <io@richiejp.com>

* feat(gallery): add privacy-filter-nemotron (f16 + q8)

GGUF conversions of OpenMed/privacy-filter-nemotron — a fine-grained English
PII token-classifier (55 categories / 221 BIOES classes), fine-tuned from
openai/privacy-filter on NVIDIA's Nemotron-PII dataset. Sibling to the existing
privacy-filter-multilingual entry, trading language breadth for category depth.

- privacy-filter-nemotron: F16 reference artifact (~2.8 GB).
- privacy-filter-nemotron-q8: Q8_0 quant (~1.64 GB) for RAM-constrained / edge
  use; description notes the size/speed tradeoff and to validate on your own
  data (a single dropped span is a PII leak).

Both run on the privacy-filter backend with known_usecases [token_classify] and
a default mask policy (min_score 0.5); operators add per-category entity_actions
as needed. sha256s taken from the HF repo's LFS object ids.

Assisted-by: Claude:claude-opus-4-8 [Claude Code]
Signed-off-by: Richard Palethorpe <io@richiejp.com>

---------

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

.github/workflows/tests-pii-ner-e2e.yml

@@ -0,0 +1,97 @@
+---
+name: 'PII NER tier E2E (live GGUF, CPU)'
+
+# Runs the real privacy-filter GGUF NER tier end-to-end on CPU — the gap the
+# hermetic tests/e2e suite cannot cover (it only exercises the in-process
+# pattern tier). Heavy (builds the C++ backend image + downloads a ~2.7 GB
+# GGUF), so it is path-filtered on PRs and otherwise runs nightly / on demand.
+#
+# This drives the container-level harness (tests/e2e-backends) via
+# `make test-extra-backend-privacy-filter`: it builds the privacy-filter image,
+# downloads the model, loads it on CPU, and asserts byte-correct, UTF-8-aligned
+# TokenClassify spans. The complementary HTTP-path specs in tests/e2e
+# (e2e_pii_ner_test.go) Skip unless PII_NER_MODEL_GGUF is wired.
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: '0 3 * * *'
+  push:
+    branches:
+      - master
+    paths:
+      - 'backend/cpp/privacy-filter/**'
+      - 'backend/Dockerfile.privacy-filter'
+      - 'core/services/routing/pii/**'
+      - 'core/services/routing/piidetector/**'
+      - 'core/backend/token_classify.go'
+      - 'core/http/endpoints/localai/pii.go'
+      - 'core/schema/pii.go'
+      - 'tests/e2e-backends/**'
+      - 'tests/e2e/e2e_pii_ner_test.go'
+      - 'tests/e2e/e2e_suite_test.go'
+      - '.github/workflows/tests-pii-ner-e2e.yml'
+  pull_request:
+    paths:
+      - 'backend/cpp/privacy-filter/**'
+      - 'backend/Dockerfile.privacy-filter'
+      - 'core/services/routing/pii/**'
+      - 'core/services/routing/piidetector/**'
+      - 'core/backend/token_classify.go'
+      - 'core/http/endpoints/localai/pii.go'
+      - 'core/schema/pii.go'
+      - 'tests/e2e-backends/**'
+      - 'tests/e2e/e2e_pii_ner_test.go'
+      - 'tests/e2e/e2e_suite_test.go'
+      - '.github/workflows/tests-pii-ner-e2e.yml'
+
+concurrency:
+  group: ci-tests-pii-ner-e2e-${{ github.event.pull_request.number || github.sha }}-${{ github.repository }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
+jobs:
+  tests-pii-ner-e2e:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go-version: ['1.25.x']
+    steps:
+      - name: Clone
+        uses: actions/checkout@v6
+        with:
+          submodules: true
+      - name: Free disk space
+        run: |
+          sudo rm -rf /usr/share/dotnet /usr/local/lib/android /opt/ghc /opt/hostedtoolcache/CodeQL || true
+          sudo docker image prune --all --force || true
+          df -h
+      - name: Configure apt mirror on runner
+        uses: ./.github/actions/configure-apt-mirror
+      - name: Setup Go ${{ matrix.go-version }}
+        uses: actions/setup-go@v5
+        with:
+          go-version: ${{ matrix.go-version }}
+          cache: false
+      - name: Proto Dependencies
+        run: |
+          curl -L -s https://github.com/protocolbuffers/protobuf/releases/download/v26.1/protoc-26.1-linux-x86_64.zip -o protoc.zip && \
+          unzip -j -d /usr/local/bin protoc.zip bin/protoc && \
+          rm protoc.zip
+          go install google.golang.org/protobuf/cmd/protoc-gen-go@v1.34.2
+          go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@1958fcbe2ca8bd93af633f11e97d44e567e945af
+          PATH="$PATH:$HOME/go/bin" make protogen-go
+      - name: Dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y build-essential
+      # Builds local-ai-backend:privacy-filter, downloads the GGUF, loads it on
+      # CPU and runs the token_classify capability spec (byte-offset contract).
+      - name: Run live PII NER backend E2E
+        run: PATH="$PATH:$HOME/go/bin" make test-extra-backend-privacy-filter
+      - name: Setup tmate session if tests fail
+        if: ${{ failure() }}
+        uses: mxschmitt/action-tmate@v3.23
+        with:
+          detached: true
+          connect-timeout-seconds: 180
+          limit-access-to-actor: true