Fix any type usage in the saas/ folder (#5934)

# Description of Changes
Ages ago I made #4835 to try and fix all the `any` type usage in the
system but never got it finished, and there were just too many to review
and ensure it still worked. There's even more now.

My new tactic is to fix folder by folder. This fixes the `any` typing in
the `saas/` folder, and also enables `no-unnecessary-type-assertion`,
which really helps reduce pointless `as` casts that AI generates when
the type is already known. I hope to expand both of these to the rest of
the folders soon, but one folder is better than none.

frontend/src/saas/auth/UseSession.tsx

@@ -114,7 +114,7 @@ export function AuthProvider({ children }: { children: ReactNode }) {
       setSubscription(subscriptionInfo)
 
       console.debug('[Auth Debug] Credits fetched successfully:', credits)
-    } catch (error: any) {
+    } catch (error: unknown) {
       console.debug('[Auth Debug] Failed to fetch credits:', error)
       // Don't set error state for credit fetching failures to avoid disrupting auth flow
       // Credits might not be available in all deployments
@@ -149,7 +149,7 @@ export function AuthProvider({ children }: { children: ReactNode }) {
         setIsPro(isProUser)
         console.debug('[Auth Debug] Pro status fetched:', isProUser)
       }
-    } catch (error: any) {
+    } catch (error: unknown) {
       console.debug('[Auth Debug] Failed to fetch pro status:', error)
       setIsPro(false) // Default to false if there's an error
     }
@@ -206,7 +206,7 @@ export function AuthProvider({ children }: { children: ReactNode }) {
       } else {
         setTrialStatus(null)
       }
-    } catch (error: any) {
+    } catch (error: unknown) {
       console.debug('[Auth Debug] Failed to fetch trial status:', error)
       setTrialStatus(null)
     }
@@ -243,7 +243,7 @@ export function AuthProvider({ children }: { children: ReactNode }) {
         setProfilePictureUrl(data.signedUrl)
         console.debug('[Auth Debug] Profile picture URL fetched successfully')
       }
-    } catch (error: any) {
+    } catch (error: unknown) {
       console.debug('[Auth Debug] Failed to fetch profile picture:', error)
       setProfilePictureUrl(null)
     }
@@ -267,7 +267,7 @@ export function AuthProvider({ children }: { children: ReactNode }) {
       const metadata = await getProfilePictureMetadata(currentSession.user.id)
       setProfilePictureMetadata(metadata)
       console.debug('[Auth Debug] Profile picture metadata fetched:', metadata)
-    } catch (error: any) {
+    } catch (error: unknown) {
       console.debug('[Auth Debug] Failed to fetch profile picture metadata:', error)
       setProfilePictureMetadata(null)
     }