fix(coder/github-upload-public-key): follow pagination when checking existing keys (#1197)

## Description

Stacked on #1193. Addresses [this review
comment](#1193 (comment)).

GitHub's key list endpoints return 30 keys per page by default, so a
Coder key beyond the first page was missed and the module tried to
upload it again. `upload_key` now requests `per_page=100` and keeps
fetching pages until it finds the key or gets a page shorter than 100.
This applies to both `/user/keys` and `/user/ssh_signing_keys`.

## Type of Change

- [ ] New module
- [ ] New template
- [x] Bug fix
- [ ] Feature/enhancement
- [ ] Documentation
- [ ] Other

## Module Information

**Path:** `registry/coder/modules/github-upload-public-key`
**New version:** `v1.2.0` (unreleased; same version as #1193)
**Breaking change:** [ ] Yes [x] No

## Testing & Validation

- [x] Tests pass (`bun test`): 10/10, with a new case where the key is
on the second page for both endpoints. This case fails on the #1193
script.
- [x] Code formatted (`bun fmt`)
- [x] Changes tested locally against real GitHub

## Related Issues

Stacked on #1193

---

> [!NOTE]
> This PR was generated by Coder Agents on behalf of @35C4n0r, using
Claude.

Author: 35C4n0r

registry/coder/modules/github-upload-public-key/main.test.ts

@@ -113,6 +113,19 @@ const setupServer = () => {
           ]);
         }
 
+        // case: key exists on the second page
+        if (req.headers.get("Authorization") === "Bearer paginated") {
+          const perPage = Number(url.searchParams.get("per_page") ?? 30);
+          const page = Number(url.searchParams.get("page") ?? 1);
+          const keys = [
+            ...Array.from({ length: perPage }, (_, i) => ({ key: `foo-${i}` })),
+            { key: "exists" },
+          ];
+          return createJSONResponse(
+            keys.slice((page - 1) * perPage, page * perPage),
+          );
+        }
+
         // case: key does not exist
         return createJSONResponse([
           {
@@ -238,6 +251,23 @@ describe("github-upload-public-key", () => {
     ]);
   });
 
+  it("finds an existing key on a later page", async () => {
+    const { id, run, uploads } = await setupContainer(undefined, {
+      key_type: "both",
+    });
+    await writeCoder(id, "echo paginated");
+
+    const exec = await run();
+    expect(exec.stdout).toContain(
+      "Your Coder public key is already a GitHub authentication key!",
+    );
+    expect(exec.stdout).toContain(
+      "Your Coder public key is already a GitHub signing key!",
+    );
+    expect(exec.exitCode).toBe(0);
+    expect(uploads).toEqual([]);
+  });
+
   it("skips existing keys when key_type is both", async () => {
     const { id, run, uploads } = await setupContainer(undefined, {
       key_type: "both",

registry/coder/modules/github-upload-public-key/run.sh

@@ -69,31 +69,38 @@ upload_key() {
   local label="$2"
 
   echo "Fetching $label keys from GitHub..."
-  local keys_response
-  keys_response=$(
-    curl -L -s \
-      -w "\n%%{http_code}" \
-      -H "Accept: application/vnd.github+json" \
-      -H "Authorization: Bearer $GITHUB_TOKEN" \
-      -H "X-GitHub-Api-Version: 2022-11-28" \
-      "$GITHUB_API_URL/user/$endpoint"
-  )
-  local keys_status keys_body
-  keys_status=$(tail -n1 <<< "$keys_response")
-  keys_body=$(sed \$d <<< "$keys_response")
-
-  if [ "$keys_status" -ne 200 ]; then
-    echo "Failed to fetch GitHub $label keys with status code $keys_status!"
-    echo "$keys_body"
-    return 1
-  fi
-
-  local match
-  match=$(jq -r --arg PUBLIC_KEY "$PUBLIC_KEY" '.[] | select(.key == $PUBLIC_KEY) | .key' <<< "$keys_body")
-  if [ "$PUBLIC_KEY" = "$match" ]; then
-    echo "Your Coder public key is already a GitHub $label key!"
-    return 0
-  fi
+  local per_page=100 page=1
+  local keys_response keys_status keys_body match count
+  while true; do
+    keys_response=$(
+      curl -L -s \
+        -w "\n%%{http_code}" \
+        -H "Accept: application/vnd.github+json" \
+        -H "Authorization: Bearer $GITHUB_TOKEN" \
+        -H "X-GitHub-Api-Version: 2022-11-28" \
+        "$GITHUB_API_URL/user/$endpoint?per_page=$per_page&page=$page"
+    )
+    keys_status=$(tail -n1 <<< "$keys_response")
+    keys_body=$(sed \$d <<< "$keys_response")
+
+    if [ "$keys_status" -ne 200 ]; then
+      echo "Failed to fetch GitHub $label keys with status code $keys_status!"
+      echo "$keys_body"
+      return 1
+    fi
+
+    match=$(jq -r --arg PUBLIC_KEY "$PUBLIC_KEY" '.[] | select(.key == $PUBLIC_KEY) | .key' <<< "$keys_body")
+    if [ "$PUBLIC_KEY" = "$match" ]; then
+      echo "Your Coder public key is already a GitHub $label key!"
+      return 0
+    fi
+
+    count=$(jq 'length' <<< "$keys_body")
+    if [ "$count" -lt "$per_page" ]; then
+      break
+    fi
+    page=$((page + 1))
+  done
 
   echo "Your Coder public key is not a GitHub $label key yet. Adding it now..."
   local upload_response