chore: v2.8.7 — Git SSH keys in tabs, safer Artifacts preview and search

- Settings → Git → Your git identity: SSH keys are one tab per host kind
  (GitHub · GitLab, AWS CodeCommit, More keys, Other hosts); opens on the
  AWS tab when only an RSA key exists.
- Artifacts: a file type the sandboxed preview cannot show (Office, zip,
  PDF) offers Download only, never a blank Preview.
- Artifacts search: `%`/`_`/`\` in a query match literally (LIKE ... ESCAPE).
- Skill frontmatter rewrite replaces a key with its continuation lines and
  quotes values YAML could misread.
- Plugin marketplace.json is read with a 1 MB streaming cap.
- Artifact lists look each owner up once.

client/src/i18n/locales/en/artifacts.json

@@ -32,6 +32,7 @@
   "copyLink": "Copy link",
   "preview": "Preview",
   "download": "Download",
+  "noPreview": "This file type cannot be shown here — download it to open it.",
   "install": "Install",
   "installs": "{{count}} installs",
   "installed": "Installed to {{path}}",

client/src/i18n/locales/en/settings.json

@@ -945,13 +945,16 @@
     "alias": "Account name",
     "aliasPlaceholder": "name (optional)",
     "aliasHint": "Leave empty for the default account of this host. Give a name (e.g. aws-prod, lowercase, no dot) for one more account: clone it as ssh://<name>/…",
-    "awsMany": "Several AWS accounts? Make one more RSA key below for each, upload it to that account, then save its SSH key ID here with an account name and that key. Clone each with ssh://<account name>/v1/repos/<repo>.",
+    "awsMany": "Several AWS accounts? Make one more RSA key in the More keys tab for each, upload it to that account, then save its SSH key ID here with an account name and that key. Clone each with ssh://<account name>/v1/repos/<repo>.",
     "moreKeysTitle": "More SSH keys",
     "moreKeysSub": "One per extra account — another AWS account, a second GitHub user. A login that names its key uses only that key.",
     "newKey": "New key",
     "keyName": "Key name",
     "keyNamePlaceholder": "e.g. aws-prod",
-    "keyType": "Key type"
+    "keyType": "Key type",
+    "tabGit": "GitHub · GitLab",
+    "tabMore": "More keys",
+    "tabOther": "Other hosts"
   },
   "gitCreds": {
     "title": "Git credentials",