Verify Rust toolchain and document oracle capabilities

.github/workflows/ci.yml

@@ -18,6 +18,25 @@ jobs:
         with:
           fetch-depth: 0
       - uses: actions-rust-lang/setup-rust-toolchain@v1
+      - name: Verify active Rust toolchain
+        run: |
+          python3 - <<'PY'
+          import subprocess
+          import tomllib
+          from pathlib import Path
+
+          expected = tomllib.loads(Path("rust-toolchain.toml").read_text())["toolchain"]["channel"]
+          active = subprocess.check_output(
+              ["rustup", "show", "active-toolchain"], text=True
+          ).split()[0]
+          host = subprocess.check_output(["rustup", "show", "host"], text=True).strip()
+
+          if active not in (expected, f"{expected}-{host}"):
+              raise SystemExit(
+                  f"Rust toolchain mismatch: expected {expected!r}, got {active!r}"
+              )
+          print(f"Verified active Rust toolchain: {active} (configured: {expected})")
+          PY
       - name: Run workspace tests
         run: cargo test --workspace
       - name: Verify committed snapshot goldens

.gitignore

@@ -1,4 +1,5 @@
 commit_out.txt
+.git_commit_msg.txt
 
 # Rust build artifacts
 target/

contracts/oracles/src/views.rs

@@ -36,6 +36,16 @@
 
 /// Named bit-flag constants for oracle contract capabilities.
 ///
+/// This unit struct is a namespace, not a typed flag set. The contract returns
+/// a `u64` bitmap as its stable ABI, which lets older clients inspect known
+/// bits while preserving unknown bits introduced by future versions. Changing
+/// the return type would change that ABI; wrapping the constants locally would
+/// still require conversion at the contract boundary.
+///
+/// Callers may combine these constants into masks, but such masks are only
+/// client-side checks: the contract emits [`SUPPORTED_CAPABILITIES`] and does
+/// not accept arbitrary capability combinations as input.
+///
 /// Each constant is a power-of-two `u64` that can be combined with `|` to
 /// form a bitmap, and isolated with `&` to test a specific capability.
 ///