docs: updating Edge Functions error codes (#48767)

<!-- ccr-slack-attribution -->
_Requested by **Kalleby Santos** · [Slack
thread](https://supabase.slack.com/archives/C02KMRX22NR/p1785949561216739?thread_ts=1785949561.216739&cid=C02KMRX22NR)_

## I have read the
[CONTRIBUTING.md](https://github.com/supabase/supabase/blob/master/CONTRIBUTING.md)
file.

YES

## What kind of change does this PR introduce?

Docs update. Adds two missing entries to the Edge Functions **Error
codes** page (`apps/docs/content/guides/functions/error-codes.mdx`).

Refs https://github.com/supabase/supabase/issues/47739

## What is the current behavior?

Neither `NOT_FOUND_FUNCTION_BLOB` nor `LOAD_FUNCTION_UNBUNDLING_ERROR`
appears on the Error codes page. Someone who gets a 404 with
`sb-error-code: NOT_FOUND_FUNCTION_BLOB` and searches the page finds
nothing — and because the response body is the same `Requested function
was not found` string that generic `NOT_FOUND` returns, the existing
`NOT_FOUND` entry reads like it covers the case when it doesn't.

## What is the new behavior?

Both codes are documented under `## Server Errors` with a cause and a
remedy, in the page's existing `**Cause:**` / `**Solution:**` shape.

- `NOT_FOUND_FUNCTION_BLOB` goes directly after `### NOT_FOUND`, since
readers hitting it will scan for `NOT_FOUND` first. The cause explains
the metadata/bundle version mismatch (concurrent or batched deploys
double-incrementing the metadata version), notes that the message is
identical to `NOT_FOUND` so the `sb-error-code` header is the
distinguisher, and links the existing [Edge Function 404 error
response](https://supabase.com/docs/guides/troubleshooting/edge-function-404-error-response)
troubleshooting guide. Solution: redeploy with the latest CLI, avoid
concurrent deploys of the same function, contact support to re-sync
metadata if it persists.
- `LOAD_FUNCTION_UNBUNDLING_ERROR` goes at the end, keeping the
`LOAD_FUNCTION_*` cluster together. Cause: the bundle was fetched but
decompression/parsing failed, which points at a corrupt or
partially-written bundle. Solution: redeploy, contact support if it
persists.

## Additional context

Both codes are real and currently emitted by
`supabase/edge-functions-ingress` (`main`):

- `NOT_FOUND_FUNCTION_BLOB` — 404, declared at `src/main/errors.ts:29`,
emitted at `src/main/cache.ts:180`
- `LOAD_FUNCTION_UNBUNDLING_ERROR` — 503, declared at
`src/main/errors.ts:27`, emitted at `src/main/cache.ts:226`

Both were introduced by supabase/edge-functions-ingress#464.

### Notes for reviewer

- **Scope.** The comment on #47739 asked only for
`NOT_FOUND_FUNCTION_BLOB`. `LOAD_FUNCTION_UNBUNDLING_ERROR` is included
because it shipped in the same ingress PR and is equally undocumented —
happy to drop it if you'd rather keep this PR to exactly what was
requested.
- **No HTTP statuses in the copy.** The 404/503 above are deliberately
left out of the page text, because the Error codes page states no HTTP
status anywhere for any code. Adding them here would be a format
departure. Easy to add if you'd prefer to start including them.
- **Message mismatch, not fixed here.**
`apps/docs/content/troubleshooting/edge-function-404-error-response.mdx`
declares `message = "Function deployment bundle not found"` for
`NOT_FOUND_FUNCTION_BLOB`, but the runtime actually emits `"Requested
function was not found"` (`cache.ts:181`), which matches the response
pasted in #47739. Left untouched in this PR — flagging it for a
follow-up.

### Checks run

- `prettier --check` on the changed file: passes.
- `supa-mdx-lint` (v0.3.2) on the changed file: no new findings. The one
remaining warning (`error-codes.mdx:11` — "Use 'view and resolve errors'
instead of 'handle errors'") is pre-existing on `master` and untouched
here.
- The `{/* supa-mdx-lint-disable Rule001HeadingCase */}` pragma at line
8 sits above both new H3s, so the uppercase headings pass.

---
_Generated by [Claude
Code](https://claude.ai/code/session_01Qw5D2wdScBN5TWuA2FgnDW)_

---------

Co-authored-by: Claude <noreply@anthropic.com>

apps/docs/content/guides/functions/error-codes.mdx

@@ -264,6 +264,21 @@ These errors indicate issues with function loading, execution, or the underlying
 
 **Solution:** Try redeploying your function and wait a few minutes to make sure all regions have been updated.
 
+### NOT_FOUND_FUNCTION_BLOB
+
+**Cause:** Your Edge Function metadata resolved, but its deployment bundle was missing from storage and could not be loaded (the metadata points at a different version than the stored bundle). This returns the same `Requested function was not found` message as `NOT_FOUND`, so the `sb-error-code` header is what distinguishes them — see [Edge Function 404 error response](/docs/guides/troubleshooting/edge-function-404-error-response).
+
+**Common causes:**
+
+- Two deploys of the same function running concurrently, double-incrementing the metadata version
+- A batch deploy using `/deploy?bundleOnly=true` where the bulk metadata update failed
+
+**Solution:**
+
+- Redeploy your function with the latest version of the Supabase CLI
+- Avoid running concurrent deploys of the same function, such as overlapping GitHub Actions runs
+- If the problem persists, contact support so your function metadata can be re-synced
+
 ### BOOT_ERROR
 
 **Cause:** Your Edge Function failed to start.
@@ -302,3 +317,12 @@ These errors indicate issues with function loading, execution, or the underlying
 
 - Try redeploying your function
 - If the problem persists, contact support
+
+### LOAD_FUNCTION_UNBUNDLING_ERROR
+
+**Cause:** Your Edge Function deployment bundle was fetched, but could not be unbundled because decompressing or parsing it failed. This usually means the bundle is corrupt or was only partially written.
+
+**Solution:**
+
+- Try redeploying your function
+- If the problem persists, contact support