fix(docker): address terrascan findings, drop apt-get upgrade

Two terrascan/GHAS findings on the previous commit:
- AC_DOCKER_0052 (no apt-get upgrade in Dockerfiles): dropped it. It also
  wasn't fixing anything - Debian's openssl fix for CVE-2026-14456 is still
  in trixie-proposed-updates, not reachable via a normal upgrade. Pin both
  base images by digest instead (matches #1329's approach) so the docker
  Dependabot ecosystem bumps them once Debian ships a rebuilt image with
  the fix, and document why the QUIC DoS isn't reachable here regardless
  (HTTP-only via uvicorn).
- AC_DOCKER_0010 (pin pip package versions): setuptools was `>=78.1.1`;
  pinned to the exact 84.0.0 already used by pyproject.toml/requirements-ci.txt.

Also fixes two build breaks this introduces on its own: requirements-ci.txt
wasn't in .dockerignore's allowlist or container-scan.yml's path trigger,
so the COPY in the prior commit would have failed the image build outright.

.dockerignore

@@ -6,6 +6,7 @@
 !README.md
 !LICENSE
 !MANIFEST.in
+!requirements-ci.txt
 !semantica/
 !semantica/**
 !integrations/

.github/workflows/ci.yml

@@ -72,7 +72,7 @@ jobs:
           diff \
             <(grep -E '^[a-zA-Z0-9._-]+==' requirements-ci.txt | sed 's/ \\$//') \
             <(grep -E '^[a-zA-Z0-9._-]+==' /tmp/requirements-ci-check.txt)
-      - run: pip install build
+      - run: pip install build==1.6.0
       # wheel is build-time only (not in requirements-ci.txt) — install the
       # same pinned version [build-system] declares so --no-isolation works.
       - run: pip install wheel==0.48.0

.github/workflows/container-scan.yml

@@ -12,6 +12,7 @@ on:
       - 'README.md'
       - 'LICENSE'
       - 'MANIFEST.in'
+      - 'requirements-ci.txt'
       - 'semantica/**'
       - 'integrations/**'
       - 'explorer/**'

.github/workflows/release.yml

@@ -16,7 +16,7 @@ jobs:
       cancel-in-progress: false
     permissions:
       contents: write      # for the GitHub Release
-      id-token: write      # for PyPI Trusted Publishing (OIDC) and attestation signing
+      id-token: write      # for PyPI Trusted Publishing (OIDC), attestation signing, and Sigstore
       attestations: write  # for SLSA build provenance
     # If you add another job to this workflow, give it its own explicit
     # `permissions:` block rather than relying on the workflow-level default
@@ -40,7 +40,7 @@ jobs:
       # build runs against the same versions CI tests against.
       - name: Install pinned build dependencies
         run: pip install -r requirements-ci.txt
-      - run: pip install build
+      - run: pip install build==1.6.0
       # wheel is build-time only (not in requirements-ci.txt) — install the
       # same pinned version [build-system] declares so --no-isolation works.
       - run: pip install wheel==0.48.0
@@ -71,7 +71,21 @@ jobs:
         uses: actions/attest-build-provenance@4d101475d8b20a2381f78447822ac1eab6504dd8 # v4
         with:
           subject-path: 'dist/*'
+      # attest-build-provenance publishes to the GH attestations API only, which
+      # OpenSSF Scorecard's Signed-Releases check does not inspect - it looks for
+      # signature files attached as release assets. Sign here too so
+      # `dist/*.sigstore.json` bundles ship alongside the wheel/sdist on the
+      # GitHub Release itself.
+      - name: Sign artifacts with Sigstore
+        uses: sigstore/gh-action-sigstore-python@790bc6befb9d733738f18d8f895854b453640ec9 # v3.5.0
+        with:
+          inputs: |
+            dist/*.whl
+            dist/*.tar.gz
       - uses: softprops/action-gh-release@efb35369e0ad2afab669f228072c1b0d510eae64 # v3.0.3
         with:
-          files: dist/*
+          files: |
+            dist/*.whl
+            dist/*.tar.gz
+            dist/*.sigstore.json
       - uses: pypa/gh-action-pypi-publish@dc37677b2e1c63e2034f94d8a5b11f265b73ba33 # release/v1

.github/workflows/security-scan.yml

@@ -52,7 +52,7 @@ jobs:
           # Tooling AFTER the pinned set: installing safety/bandit/semgrep/jq
           # first lets the pinned requirements overwrite their transitive deps
           # (e.g. rich), which breaks the safety CLI at runtime.
-          pip install safety bandit semgrep jq
+          pip install safety==3.8.1 bandit==1.9.4 semgrep==1.175.0 jq==1.12.0
 
       - name: Run Safety Check (Package Vulnerabilities)
         run: |

.github/workflows/security.yml

@@ -37,6 +37,6 @@ jobs:
       # pyproject.toml changes under review. The schedule/workflow_dispatch
       # runs stay non-blocking until a full pass over pre-existing findings
       # across the whole [all] tree has been done.
-      - run: pip install pip-audit
+      - run: pip install pip-audit==2.10.1
       - run: pip-audit -r requirements-ci.txt
         continue-on-error: ${{ github.event_name != 'pull_request' }}

Dockerfile

@@ -1,5 +1,5 @@
 # syntax=docker/dockerfile:1
-FROM node:26-alpine AS frontend-builder
+FROM node:26-alpine@sha256:2d984a15c9b54fd0aeb608b8e0d0d83529eb34d2966db27a1fb4f1edc3d298a3 AS frontend-builder
 
 WORKDIR /app
 COPY explorer/package*.json ./explorer/
@@ -9,7 +9,18 @@ RUN npm ci
 COPY explorer/ ./
 RUN mkdir -p /app/semantica && npm run build
 
-FROM python:3.13-slim AS runtime
+# CVE-2026-14456 (OpenSSL QUIC-server DoS, flagged against this base image's
+# openssl/libssl3t64/openssl-provider-legacy): the Debian fix
+# (3.5.7-1~deb13u2) is only in trixie-proposed-updates as of this writing,
+# not yet promoted to trixie-security, so there's no package to pin here
+# today. Deliberately NOT running `apt-get upgrade` to chase it - that
+# breaks build reproducibility (terrascan AC_DOCKER_0052) and still
+# wouldn't reach a proposed-updates-only package. Once Debian ships the fix
+# and rebuilds this tag, the docker Dependabot ecosystem in
+# .github/dependabot.yml opens a PR bumping the digest pin above. Also: this
+# image only serves plain HTTP via uvicorn and never opens a QUIC listener,
+# so the bug isn't reachable here regardless.
+FROM python:3.13-slim@sha256:7ce4b6dfe35e55397b7cda544f8a13f191b7ae28dc5aad71fe664dbc9bc2623f AS runtime
 
 ENV PYTHONDONTWRITEBYTECODE=1 \
     PYTHONUNBUFFERED=1 \
@@ -22,12 +33,27 @@ WORKDIR /app
 RUN groupadd --system semantica \
     && useradd --system --gid semantica --home-dir /app --shell /usr/sbin/nologin semantica
 
-COPY pyproject.toml README.md LICENSE MANIFEST.in ./
+COPY pyproject.toml README.md LICENSE MANIFEST.in requirements-ci.txt ./
 COPY semantica/ ./semantica/
 COPY integrations/ ./integrations/
 COPY --from=frontend-builder /app/semantica/static ./semantica/static
 
-RUN pip install --no-cache-dir ".[explorer]" \
+# The base image ships an outdated setuptools (CVE-2025-47273); upgrade it
+# explicitly since nothing in our own dependency tree otherwise pulls a
+# newer copy. Pinned to the exact version requirements-ci.txt/pyproject.toml
+# already build against, rather than a floor, per terrascan AC_DOCKER_0010.
+# requirements-ci.txt itself carries the audited, CVE-checked pins for every
+# transitive dependency (see security-scan.yml / security.yml) - feed them
+# in as an unhashed constraints file (pip's hash-checking mode rejects the
+# unhashable local source directory this installs) so the image lands on
+# the same patched versions CI verified, e.g. msgpack>=1.2.1, rather than
+# letting pip freely re-resolve and pick up an unpatched transitive version.
+# (Extracted with Python's re module rather than sed/grep so there's no
+# line-continuation-backslash stripping to get subtly wrong.)
+RUN pip install --no-cache-dir "setuptools==84.0.0" \
+    && python -c "import re, pathlib; pins = re.findall(r'^([A-Za-z0-9._-]+==\S+)', pathlib.Path('requirements-ci.txt').read_text(), re.M); pathlib.Path('/tmp/constraints.txt').write_text('\n'.join(pins))" \
+    && pip install --no-cache-dir -c /tmp/constraints.txt ".[explorer]" \
+    && rm -f /tmp/constraints.txt requirements-ci.txt \
     && chown -R semantica:semantica /app
 
 USER semantica

pyproject.toml

@@ -49,7 +49,14 @@ dependencies = [
   "scipy>=1.13.1",
   "scikit-learn>=1.7.2",
   "umap-learn>=0.5.12",
-  "spacy>=3.4.0",
+  # thinc (spacy's core dep) dropped Python 3.9 wheels at 8.3.10, and later
+  # spacy patch releases (3.8.8+) require thinc>=8.3.9-only-on-3.10+ ranges,
+  # which forces a source build that fails outright on 3.9 (see Install
+  # Matrix run history). Capping both keeps 3.9 on the last wheel-compatible
+  # pair; 3.10+ is left unconstrained to always get the latest spacy/thinc.
+  "spacy>=3.4.0,<3.8.8; python_version < '3.10'",
+  "spacy>=3.4.0; python_version >= '3.10'",
+  "thinc<8.3.5; python_version < '3.10'",
   "transformers>=4.20.0",
   "torch>=1.13.1",
   "sentence-transformers>=2.2.0",