fix: Phase 7d - fix null/undefined handling (28 -> 24 errors)

Fixed multiple null/undefined type errors by adding proper null checks
and default values.

Changes:
1. CharacterRep.svelte:
   - Changed import from '$lib/types/enums' to '$lib/utils/element'
   - getElementClass in utils/element accepts undefined, enums version doesn't

2. ItemHeader.svelte:
   - Convert null to undefined for gridUncapLevel and gridTranscendence
   - getCharacterPose expects 'number | undefined', not 'number | null | undefined'

3. UncapStatusDisplay.svelte:
   - Added null coalescing for transcendenceStep check
   - Changed from `transcendenceStep > 0` to `(transcendenceStep ?? 0) > 0`

4. base.adapter.ts:
   - Provide default no-op function for optional onError callback
   - Required<AdapterOptions> needs all properties defined

Result: 28 → 24 errors (-4)

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

Co-Authored-By: Claude <noreply@anthropic.com>

src/lib/api/adapters/base.adapter.ts

@@ -68,7 +68,7 @@ export abstract class BaseAdapter {
 			timeout: options.timeout ?? 30000,
 			retries: options.retries ?? 3,
 			cacheTime: options.cacheTime ?? 0,
-			onError: options.onError
+			onError: options.onError ?? (() => {})
 		}
 	}
 

src/lib/components/reps/CharacterRep.svelte

@@ -1,7 +1,7 @@
 <script lang="ts">
 	import type { Party, GridWeapon, GridCharacter } from '$lib/types/api/party'
 	import type { Job } from '$lib/types/api/entities'
-	import { getElementClass } from '$lib/types/enums'
+	import { getElementClass } from '$lib/utils/element'
 	import { getCharacterImageWithPose } from '$lib/utils/images'
 	import { getJobPortraitUrl, Gender } from '$lib/utils/jobUtils'
 

src/lib/components/sidebar/details/ItemHeader.svelte

@@ -23,7 +23,7 @@
 		const id = itemData?.granblueId
 
 		if (type === 'character') {
-			const pose = getCharacterPose(gridUncapLevel, gridTranscendence)
+			const pose = getCharacterPose(gridUncapLevel ?? undefined, gridTranscendence ?? undefined)
 			return getCharacterDetailImage(id, pose)
 		} else if (type === 'weapon') {
 			return getWeaponBaseImage(id)

src/lib/components/sidebar/modifications/UncapStatusDisplay.svelte

@@ -92,7 +92,7 @@
           <span class="badge" class:active={(uncapLevel ?? 0) >= 5}>ULB</span>
         {/if}
         {#if transcendence}
-          <span class="badge" class:active={transcendenceStep > 0}>Trans</span>
+          <span class="badge" class:active={(transcendenceStep ?? 0) > 0}>Trans</span>
         {/if}
         {#if !flb && !ulb && !transcendence}
           <span class="badge standard">Standard</span>