fix(mcp-store): make Install gating opt-in — only block on a hard test failure

The previous PR (`920735f`) gated Install on a successful Test
connection, mirroring the wizard's Step 3 gate. Wrong call for the
store: catalog templates ship with curated URLs and the backend's
`install_template` already runs its own probe + rejects on hard
failure, so a forced test before Install is just friction — for
public/no-auth templates like AWS Documentation it adds an extra
click for zero validation benefit.

New gating logic on the Install button:

- No test result yet → enabled (the common path)
- Test passed (`success` true) → enabled
- Test soft-success (`requires_auth` true, OAuth/PAT) → enabled
- Test hard-failed → disabled, with a tooltip explaining why
  (saves the user one round-trip we know would 400)

Test connection stays as an optional preview that surfaces the
upstream's tool list before commit, useful for unfamiliar templates.

The /servers wizard's Step 3 gate is unchanged — there the URL is
typed by the operator, so the test result is the *only* thing
validating the input.

i18n: dropped `mcpServers.mustTestFirst` from the store install
tooltip (it was wrong even before — that string is the wizard's
contract). New `mcpStore.installBlockedByTestFailure` describes the
narrow case where Install is actually disabled.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: fylorn

web/src/i18n/en.json

@@ -140,6 +140,7 @@
     "oauthCredentialsTitle": "OAuth client credentials",
     "oauthCredentialsHint": "From your OAuth app on {{issuer}}. Templates ship the issuer + endpoints; you supply the client_id and secret.",
     "advancedSection": "Advanced (custom headers)",
+    "installBlockedByTestFailure": "Connection test failed. Fix the error or clear the test result before installing.",
     "endpointUrl": "Endpoint URL",
     "authInstructions": "Auth Instructions",
     "deployInstructions": "Deployment Instructions",

web/src/i18n/zh.json

@@ -140,6 +140,7 @@
     "oauthCredentialsTitle": "OAuth 客户端凭证",
     "oauthCredentialsHint": "来自你在 {{issuer}} 上的 OAuth 应用。模板提供 issuer 与端点；你提供 client_id 和 secret。",
     "advancedSection": "高级（自定义请求头）",
+    "installBlockedByTestFailure": "连接测试失败。请修复错误或重新测试后再安装。",
     "endpointUrl": "端点地址",
     "authInstructions": "认证说明",
     "deployInstructions": "部署说明",

web/src/routes/mcp/store.tsx

@@ -553,10 +553,25 @@ export function McpStorePage() {
               </Button>
               <Button
                 type="submit"
-                disabled={installing || !(testResult?.success || testResult?.requires_auth)}
+                // Store templates ship with curated URLs and the
+                // backend's `install_template` runs its own probe, so
+                // the Test button is an optional *preview* (it shows
+                // the tool list before commit) rather than a gate.
+                // Only block Install when the user explicitly tested
+                // and got a hard failure — at that point we know the
+                // install would fail too, so saving them the click is
+                // friendlier than letting the backend reject.
+                disabled={
+                  installing
+                  || (testResult != null
+                      && !testResult.success
+                      && !testResult.requires_auth)
+                }
                 title={
-                  !(testResult?.success || testResult?.requires_auth)
-                    ? t('mcpServers.mustTestFirst')
+                  testResult != null
+                  && !testResult.success
+                  && !testResult.requires_auth
+                    ? t('mcpStore.installBlockedByTestFailure')
                     : undefined
                 }
               >