fix: base64 uploads, audit log noise, and stale chunk reloads (#69)

## Summary

- **Base64 cover image uploads broken for books, shows, manga, and music** — a premature `validateStringLength` check ran before the data URL detection, rejecting all base64 images with a 2,048-char URL limit error. Also fixed the size calculation to extract only the base64 portion after the comma (matching the correct pattern already in `game.service.ts`).
- **Audit log flooded with expected 401s on `/api/auth/me`** — these occur during normal token refresh flow and are not genuine security events. Excluded this URL from the global 401/403 audit log handler.
- **ChunkLoadError spam after deployments** — when Angular lazy-loaded chunks are missing (stale cache after a redeploy), the global error handler now detects `ChunkLoadError` and silently reloads the page instead of logging the error and sending it to the API/Discord.

## Test plan

- [ ] Upload a base64 cover image for a book, show, manga, and music item — should succeed
- [ ] Verify `/api/auth/me` 401s no longer appear in the audit log
- [ ] Deploy a new build and confirm stale-chunk users are silently reloaded

✨ This PR was created with help from Hikari~ 🌸

Reviewed-on: #69
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

api/src/app/services/book.service.ts

@@ -36,10 +36,6 @@ export class BookService {
     if (!validateStringLength(data.notes, MAX_LENGTHS.NOTES)) {
       throw new Error(`Notes must be ${MAX_LENGTHS.NOTES} characters or less.`);
     }
-    if (!validateStringLength(data.coverImage, MAX_LENGTHS.URL)) {
-      throw new Error(`Cover image URL must be ${MAX_LENGTHS.URL} characters or less.`);
-    }
-
     // Validate rating
     if (!validateRating(data.rating)) {
       throw new Error("Rating must be an integer between 0 and 10.");
@@ -47,7 +43,11 @@ export class BookService {
 
     if (data.coverImage) {
       if (data.coverImage.startsWith("data:")) {
-        const sizeInBytes = data.coverImage.length * 0.75;
+        const base64Data = data.coverImage.split(",")[1];
+        if (!base64Data) {
+          throw new Error("Invalid image data URL format.");
+        }
+        const sizeInBytes = base64Data.length * 0.75;
         if (sizeInBytes > MAX_LENGTHS.DATA_URL) {
           throw new Error("Cover image must be under 5MB.");
         }

api/src/app/services/manga.service.ts

@@ -33,10 +33,6 @@ export class MangaService {
     if (!validateStringLength(data.notes, MAX_LENGTHS.NOTES)) {
       throw new Error(`Notes must be ${MAX_LENGTHS.NOTES} characters or less.`);
     }
-    if (!validateStringLength(data.coverImage, MAX_LENGTHS.URL)) {
-      throw new Error(`Cover image URL must be ${MAX_LENGTHS.URL} characters or less.`);
-    }
-
     // Validate rating
     if (!validateRating(data.rating)) {
       throw new Error("Rating must be an integer between 0 and 10.");
@@ -45,7 +41,11 @@ export class MangaService {
     // Validate cover image URL
     if (data.coverImage) {
       if (data.coverImage.startsWith("data:")) {
-        const sizeInBytes = data.coverImage.length * 0.75;
+        const base64Data = data.coverImage.split(",")[1];
+        if (!base64Data) {
+          throw new Error("Invalid image data URL format.");
+        }
+        const sizeInBytes = base64Data.length * 0.75;
         if (sizeInBytes > MAX_LENGTHS.DATA_URL) {
           throw new Error("Cover image must be under 5MB.");
         }

api/src/app/services/music.service.ts

@@ -33,10 +33,6 @@ export class MusicService {
     if (!validateStringLength(data.notes, MAX_LENGTHS.NOTES)) {
       throw new Error(`Notes must be ${MAX_LENGTHS.NOTES} characters or less.`);
     }
-    if (!validateStringLength(data.coverArt, MAX_LENGTHS.URL)) {
-      throw new Error(`Cover art URL must be ${MAX_LENGTHS.URL} characters or less.`);
-    }
-
     // Validate rating
     if (data.rating !== undefined && !validateRating(data.rating)) {
       throw new Error("Rating must be an integer between 0 and 10.");
@@ -45,7 +41,11 @@ export class MusicService {
     // Validate cover art URL
     if (data.coverArt) {
       if (data.coverArt.startsWith("data:")) {
-        const sizeInBytes = data.coverArt.length * 0.75;
+        const base64Data = data.coverArt.split(",")[1];
+        if (!base64Data) {
+          throw new Error("Invalid image data URL format.");
+        }
+        const sizeInBytes = base64Data.length * 0.75;
         if (sizeInBytes > MAX_LENGTHS.DATA_URL) {
           throw new Error("Cover image must be under 5MB.");
         }

api/src/app/services/show.service.ts

@@ -30,10 +30,6 @@ export class ShowService {
     if (!validateStringLength(data.notes, MAX_LENGTHS.NOTES)) {
       throw new Error(`Notes must be ${MAX_LENGTHS.NOTES} characters or less.`);
     }
-    if (!validateStringLength(data.coverImage, MAX_LENGTHS.URL)) {
-      throw new Error(`Cover image URL must be ${MAX_LENGTHS.URL} characters or less.`);
-    }
-
     // Validate rating
     if (!validateRating(data.rating)) {
       throw new Error("Rating must be an integer between 0 and 10.");
@@ -42,7 +38,11 @@ export class ShowService {
     // Validate cover image URL
     if (data.coverImage) {
       if (data.coverImage.startsWith("data:")) {
-        const sizeInBytes = data.coverImage.length * 0.75;
+        const base64Data = data.coverImage.split(",")[1];
+        if (!base64Data) {
+          throw new Error("Invalid image data URL format.");
+        }
+        const sizeInBytes = base64Data.length * 0.75;
         if (sizeInBytes > MAX_LENGTHS.DATA_URL) {
           throw new Error("Cover image must be under 5MB.");
         }