CI builds tests and lints with a ci profile instead of --release

Light optimisation (deps at 2), line tables only, no LTO, debug assertions off (truck's debug-only
checks reject valid geometry, the only reason tests used --release). Cold full `cargo xtask ci`: 14 min
with all 647 tests passing; the oracle, step-corpus and app builds stay on --release.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RjGw4gA5ZvKrU8MQP6sBgT

.github/workflows/ci.yml

@@ -90,7 +90,7 @@ jobs:
       - uses: Swatinem/rust-cache@v2
         with:
           key: native-clippy
-      - run: cargo clippy --workspace --all-targets --release --locked -- -D warnings
+      - run: cargo clippy --workspace --all-targets --profile ci --locked -- -D warnings
 
   tests:
     name: Native Linux tests
@@ -105,9 +105,9 @@ jobs:
         with:
           key: native-tests
       - name: Compile tests
-        run: cargo test --workspace --release --locked --no-run
+        run: cargo test --workspace --profile ci --locked --no-run
       - name: Run tests
-        run: cargo test --workspace --release --locked
+        run: cargo test --workspace --profile ci --locked
 
   # Preserve the existing check name for branch protection, including docs-only PRs.
   ci: