hardening: audit remediation — hostile-input bounds, model_hash gate, dependency advisories, CI gates

.github/dependabot.yml

@@ -0,0 +1,50 @@
+# dependabot configuration. simple by design: weekly cadence, capped pr count,
+# explicit scope. update when adding new package ecosystems.
+#
+# pip is intentionally absent: pyproject.toml declares only `>=` floors in a
+# PEP 735 dependency group (no pins, no lockfile), so version updates would
+# have nothing to bump. add the ecosystem if pinned requirements or a Python
+# lockfile ever land.
+#
+# docs: https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file
+
+version: 2
+
+updates:
+  # rust workspace at the repo root. Cargo.lock is committed, so updates
+  # target the exact resolved versions the CLI binary ships with.
+  - package-ecosystem: cargo
+    directory: /
+    schedule:
+      interval: weekly
+      day: monday
+    open-pull-requests-limit: 5
+    labels:
+      - dependencies
+      - rust
+    commit-message:
+      prefix: cargo
+      include: scope
+    groups:
+      patch-and-minor:
+        update-types:
+          - patch
+          - minor
+
+  # github actions workflows (.github/workflows/).
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
+      day: monday
+    open-pull-requests-limit: 3
+    labels:
+      - dependencies
+      - github-actions
+    commit-message:
+      prefix: actions
+      include: scope
+    groups:
+      actions:
+        patterns:
+          - "*"

.github/workflows/ci.yml

@@ -59,14 +59,12 @@ jobs:
       - run: ruff check python tests
 
   audit:
-    name: cargo-audit (advisory)
+    name: cargo-audit
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
       - run: cargo install cargo-audit --locked
-      # Informational until the pre-existing advisory backlog is triaged: it
-      # surfaces vulnerable deps in the logs without blocking merges. Flip to a
-      # blocking check once the tree is clean.
+      # Blocking: the advisory backlog was cleared with the pyo3 0.29 bump, so
+      # any new advisory against the committed Cargo.lock should fail CI.
       - run: cargo audit
-        continue-on-error: true

crates/nest-python/Cargo.toml

@@ -10,10 +10,10 @@ name = "_nest"
 crate-type = ["cdylib"]
 
 [dependencies]
-pyo3 = { version = "0.28", features = ["abi3-py312"] }
+pyo3 = { version = "0.29", features = ["abi3-py312"] }
 nest-format = { workspace = true }
 nest-runtime = { workspace = true }
 serde_json = { workspace = true }
 
 [build-dependencies]
-pyo3-build-config = "0.28"
+pyo3-build-config = "0.29"