initial project scaffold

Rust workspace with nomina-core (rename engine) and nomina-app (Tauri v2 shell).
React/TypeScript frontend with tabbed rule panels, virtual-scrolled file list,
and Zustand state management. All 9 rule types implemented with 25 passing tests.

ui/src/components/rules/ReplaceTab.tsx

@@ -0,0 +1,82 @@
+import { useRuleStore } from "../../stores/ruleStore";
+import type { ReplaceConfig, StepMode } from "../../types/rules";
+
+export function ReplaceTab() {
+  const rule = useRuleStore((s) => s.rules.replace) as ReplaceConfig;
+  const updateRule = useRuleStore((s) => s.updateRule);
+
+  const update = (changes: Partial<ReplaceConfig>) => updateRule("replace", changes);
+
+  return (
+    <div className="flex flex-col gap-3 text-xs">
+      <div className="flex gap-3">
+        <label className="flex flex-col flex-1 gap-1">
+          <span style={{ color: "var(--text-secondary)" }}>Find</span>
+          <input
+            type="text"
+            value={rule.search}
+            onChange={(e) => update({ search: e.target.value })}
+            className="px-2 py-1.5 rounded border"
+            style={{
+              background: "var(--bg-primary)",
+              borderColor: "var(--border)",
+              color: "var(--text-primary)",
+            }}
+            placeholder="Text to find..."
+          />
+        </label>
+        <label className="flex flex-col flex-1 gap-1">
+          <span style={{ color: "var(--text-secondary)" }}>Replace with</span>
+          <input
+            type="text"
+            value={rule.replace_with}
+            onChange={(e) => update({ replace_with: e.target.value })}
+            className="px-2 py-1.5 rounded border"
+            style={{
+              background: "var(--bg-primary)",
+              borderColor: "var(--border)",
+              color: "var(--text-primary)",
+            }}
+            placeholder="Replacement text..."
+          />
+        </label>
+      </div>
+
+      <div className="flex items-center gap-4">
+        <label className="flex items-center gap-1.5 cursor-pointer">
+          <input
+            type="checkbox"
+            checked={rule.match_case}
+            onChange={(e) => update({ match_case: e.target.checked })}
+          />
+          <span>Match case</span>
+        </label>
+        <label className="flex items-center gap-1.5 cursor-pointer">
+          <input
+            type="checkbox"
+            checked={rule.first_only}
+            onChange={(e) => update({ first_only: e.target.checked })}
+          />
+          <span>First only</span>
+        </label>
+
+        <div className="flex-1" />
+
+        <div className="flex items-center gap-2">
+          <span style={{ color: "var(--text-secondary)" }}>Mode:</span>
+          {(["Simultaneous", "Sequential"] as StepMode[]).map((mode) => (
+            <label key={mode} className="flex items-center gap-1 cursor-pointer">
+              <input
+                type="radio"
+                name="replace-mode"
+                checked={rule.step_mode === mode}
+                onChange={() => update({ step_mode: mode })}
+              />
+              <span>{mode}</span>
+            </label>
+          ))}
+        </div>
+      </div>
+    </div>
+  );
+}