test(cache): cover rejected remote cache uploads

crates/vt_bin/tests/e2e_snapshots/fixtures/remote_cache/snapshots.toml

@@ -574,6 +574,83 @@ steps = [
   ], comment = "The details include why the token request failed." },
 ]
 
+[[e2e]]
+name = "pull_request_upload"
+cfg = "not(windows)"
+ignore = true
+steps = [
+  [
+    "remote-cache-server",
+    "start",
+  ],
+  { argv = [
+    "remote-cache-server",
+    "run",
+    "--github-actions",
+    "vt",
+    "run",
+    "build",
+  ], envs = [
+    [
+      "VP_REMOTE_CACHE",
+      "read-write",
+    ],
+    [
+      "ACTIONS_ID_TOKEN_REQUEST_TOKEN",
+      "pull-request",
+    ],
+    [
+      "VP_RUN_INTERNAL_HIDE_PENDING_UPLOADS",
+      "1",
+    ],
+  ], comment = "The job runs for a pull request, so its token doesn't satisfy the write policy and the backend rejects the upload. The task succeeds." },
+  { argv = [
+    "vt",
+    "run",
+    "--last-details",
+  ], comment = "The details include the backend's message." },
+  [
+    "remote-cache-server",
+    "stop",
+  ],
+]
+
+[[e2e]]
+name = "upload_without_token"
+cfg = "not(windows)"
+ignore = true
+steps = [
+  [
+    "remote-cache-server",
+    "start",
+  ],
+  { argv = [
+    "remote-cache-server",
+    "run",
+    "vt",
+    "run",
+    "build",
+  ], envs = [
+    [
+      "VP_REMOTE_CACHE",
+      "read-write",
+    ],
+    [
+      "VP_RUN_INTERNAL_HIDE_PENDING_UPLOADS",
+      "1",
+    ],
+  ], comment = "Outside GitHub Actions, the upload has no token, so the backend rejects it. The task succeeds." },
+  { argv = [
+    "vt",
+    "run",
+    "--last-details",
+  ], comment = "The details include the backend's message." },
+  [
+    "remote-cache-server",
+    "stop",
+  ],
+]
+
 [[e2e]]
 name = "read_invalid_endpoint"
 steps = [

crates/vt_bin/tests/e2e_snapshots/fixtures/remote_cache/snapshots/pull_request_upload.md

@@ -0,0 +1,46 @@
+# pull_request_upload
+
+## `remote-cache-server start`
+
+```
+```
+
+## `VP_REMOTE_CACHE=read-write ACTIONS_ID_TOKEN_REQUEST_TOKEN=pull-request VP_RUN_INTERNAL_HIDE_PENDING_UPLOADS=1 remote-cache-server run --github-actions vt run build`
+
+The job runs for a pull request, so its token doesn't satisfy the write policy and the backend rejects the upload. The task succeeds.
+
+```
+$ vtt write-file dist/output.txt built
+
+---
+vt run: remote-cache#build not uploaded to the remote cache: HTTP status 403. (Run `vt run --last-details` for full details)
+[remote-cache] POST /fetch 404
+[remote-cache] POST /store 403
+```
+
+## `vt run --last-details`
+
+The details include the backend's message.
+
+```
+
+━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+    Vite+ Task Runner • Execution Summary
+━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+Statistics:   1 task • 0 cache hits • 1 cache miss
+Performance:  0% cache hit rate
+
+Task Details:
+────────────────────────────────────────────────
+  [1] remote-cache#build: $ vtt write-file dist/output.txt built ✓
+      → Cache miss: no previous cache entry found
+      ⚠ Not uploaded to the remote cache: HTTP status 403
+        ↳ Write not permitted
+━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+```
+
+## `remote-cache-server stop`
+
+```
+```

crates/vt_bin/tests/e2e_snapshots/fixtures/remote_cache/snapshots/upload_without_token.md

@@ -0,0 +1,46 @@
+# upload_without_token
+
+## `remote-cache-server start`
+
+```
+```
+
+## `VP_REMOTE_CACHE=read-write VP_RUN_INTERNAL_HIDE_PENDING_UPLOADS=1 remote-cache-server run vt run build`
+
+Outside GitHub Actions, the upload has no token, so the backend rejects it. The task succeeds.
+
+```
+$ vtt write-file dist/output.txt built
+
+---
+vt run: remote-cache#build not uploaded to the remote cache: HTTP status 401. (Run `vt run --last-details` for full details)
+[remote-cache] POST /fetch 404
+[remote-cache] POST /store 401
+```
+
+## `vt run --last-details`
+
+The details include the backend's message.
+
+```
+
+━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+    Vite+ Task Runner • Execution Summary
+━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+Statistics:   1 task • 0 cache hits • 1 cache miss
+Performance:  0% cache hit rate
+
+Task Details:
+────────────────────────────────────────────────
+  [1] remote-cache#build: $ vtt write-file dist/output.txt built ✓
+      → Cache miss: no previous cache entry found
+      ⚠ Not uploaded to the remote cache: HTTP status 401
+        ↳ Invalid credentials
+━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+```
+
+## `remote-cache-server stop`
+
+```
+```