feat(web): collapse the schema-portability section by default (#2205)

The Tools tab rendered every schema-portability finding, always open, above
the argument form. On a server whose schemas are broadly unportable that put
the same wall of text ahead of every tool's first input — and the findings
address the server author, not the caller trying to fill the form.

The section now opens collapsed behind the same disclosure heading the Skills
pane's Conformance section uses, with an `N error(s), M warning(s)` badge. The
expand choice is global rather than per tool (`useSchemaFindingsExpanded`,
stored as `inspector.schemaFindings.expanded`): this panel is reused across
selections, so a per-tool disclosure would re-collapse on every click and
reproduce the same scrolling. The badge stays visible while collapsed and the
tool-list severity icon is untouched, so nothing about a tool's standing is
hidden by the closed state.

Two neighbouring fixes on the same panel:

- `JsonEditor` frames Ace in a bordered `Paper`. Ace paints its background edge
  to edge with nothing around it, so "Edit as JSON" replaced a column of
  bordered inputs with one borderless slab.
- `ToolDetailPanel`'s body `ScrollArea` overrode the app-wide `type="scroll"`
  default with `type="auto"`, parking a permanent bar down the side of any tool
  whose form is taller than the panel. `offsetScrollbars` stays, so the form
  does not shift sideways when the bar fades in.

`test-servers/configs/unportable-schemas-many-http.json` reproduces the
original complaint: the same four presets as `unportable-schemas-http.json`
carrying 26 findings rather than 5.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DU3QYnc95g6EM4vo3hYNet
Signed-off-by: cliffhall <cliff@futurescale.com>

test-servers/configs/unportable-schemas-many-http.json

@@ -0,0 +1,86 @@
+{
+  "serverInfo": {
+    "name": "unportable-schemas-volume-showcase",
+    "version": "1.0.0"
+  },
+  "tools": [
+    { "preset": "echo" },
+    { "preset": "add" },
+    { "preset": "get_weather" },
+    { "preset": "get_temp" }
+  ],
+  "rawToolSchemas": {
+    "echo": {
+      "inputSchema": {
+        "type": "object",
+        "properties": {
+          "message": { "type": "string" },
+          "prefix": { "type": ["string", "null"] },
+          "suffix": { "type": ["string", "null"] },
+          "repeat": { "type": ["integer", "null"] },
+          "uppercase": { "type": ["boolean", "null"] },
+          "separator": { "type": ["string", "null"] },
+          "locale": { "type": ["string", "null"] },
+          "metadata": {},
+          "context": { "description": "Anything the caller wants to attach." },
+          "passthrough": true,
+          "envelope": { "$ref": "https://example.com/schemas/envelope.json" },
+          "tags": {
+            "type": "array",
+            "items": { "type": ["string", "null"] }
+          }
+        },
+        "required": ["message"]
+      }
+    },
+    "add": {
+      "inputSchema": {
+        "type": "object",
+        "properties": {
+          "a": {
+            "type": "number",
+            "$ref": "https://example.com/schemas/number.json"
+          },
+          "b": {
+            "type": "number",
+            "$ref": "https://example.com/schemas/number.json"
+          },
+          "precision": { "type": ["integer", "null"] },
+          "rounding": { "type": ["string", "null"] },
+          "trace": {},
+          "audit": true
+        },
+        "required": ["a", "b"]
+      }
+    },
+    "get_weather": {
+      "inputSchema": {
+        "type": "object",
+        "properties": {
+          "city": { "type": "string" },
+          "units": { "type": ["string", "null"] },
+          "at": { "type": ["string", "null"] },
+          "hints": {},
+          "provider": { "$ref": "https://example.com/schemas/provider.json" }
+        },
+        "required": ["city"]
+      }
+    },
+    "get_temp": {
+      "outputSchema": {
+        "type": "object",
+        "properties": {
+          "temperature": { "type": ["number", "null"] },
+          "unit": { "type": ["string", "null"] },
+          "city": { "type": ["string", "null"] },
+          "data": true,
+          "diagnostics": {}
+        }
+      }
+    }
+  },
+  "transport": {
+    "type": "streamable-http",
+    "port": 6613
+  }
+}