fix(tests): use pull() in pattern harness for pull mode compatibility

In pull mode, .get() returns cached values without triggering
computation of dirty dependencies. Changed the pattern harness to use
.pull() which properly establishes an effect and waits for the
scheduler to compute all transitive dependencies.

This fixes 27/28 failing generated-patterns integration tests.
One test (counter-when-unless-operators) still fails due to a
deeper issue with nested lift computations through references.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: seefeldb

packages/generated-patterns/integration/pattern-harness.ts

@@ -117,7 +117,8 @@ export async function runPatternScenario(scenario: PatternIntegrationScenario) {
         (cell, segment) => cell.key(segment),
         result,
       );
-      const actual = targetCell.get();
+      // Use pull() in pull mode to ensure all dependencies are computed
+      const actual = await targetCell.pull();
       expect(actual, `${name}:${stepIndex}:${assertion.path}`)
         .toEqual(assertion.value);
     }