fix: replace any types with proper types across codebase

Replace ~100 `any` usages with proper types: use existing interfaces
(RecipeModelType, BriefRecipeType, IPayment, etc.), Record<string, unknown>
for dynamic objects, unknown for catch clauses with proper narrowing,
and inline types for callbacks. Remaining `any` types are in Svelte
components and cases where mongoose document mutation requires casts.

src/routes/cospend/payments/add/+page.server.ts

@@ -219,8 +219,8 @@ export const actions: Actions = {
       // Success - redirect to dashboard
       throw redirect(303, '/cospend');
 
-    } catch (error: any) {
-      if (error.status === 303) throw error; // Re-throw redirect
+    } catch (error: unknown) {
+      if (error && typeof error === 'object' && 'status' in error && (error as { status: number }).status === 303) throw error; // Re-throw redirect
       
       console.error('Error creating payment:', error);
       return fail(500, {

src/routes/cospend/settle/+page.server.ts

@@ -114,13 +114,14 @@ export const actions: Actions = {
 
       // Redirect back to dashboard on success
       throw redirect(303, '/cospend');
-    } catch (error: any) {
-      if (error.status === 303) {
+    } catch (error: unknown) {
+      if (error && typeof error === 'object' && 'status' in error && (error as { status: number }).status === 303) {
         throw error; // Re-throw redirect
       }
 
+      const message = error instanceof Error ? error.message : String(error);
       return fail(500, {
-        error: error.message,
+        error: message,
         values: {
           settlementType,
           fromUser,