Migrate gists toolset to modelcontextprotocol/go-sdk

- Remove //go:build ignore tags from gists.go and gists_test.go
- Update imports to use modelcontextprotocol/go-sdk instead of mark3labs/mcp-go
- Migrate all 4 tools (ListGists, GetGist, CreateGist, UpdateGist):
  - Updated tool definitions to use jsonschema.Schema for InputSchema
  - Changed handler signatures to new SDK format with generics
  - Updated parameter extraction to use args map instead of request object
  - Replaced result helpers with utils package equivalents
- Updated all tests to match new handler signatures
- Added toolsnap tests for all 4 tools
- Added parseISOTimestamp utility function to minimal_types.go
- Created toolsnaps for all 4 tools

Related to #1428

Co-authored-by: omgitsads <4619+omgitsads@users.noreply.github.com>

Author: Copilot

pkg/github/__toolsnaps__/create_gist.snap

@@ -0,0 +1,33 @@
+{
+  "annotations": {
+    "title": "Create Gist"
+  },
+  "description": "Create a new gist",
+  "inputSchema": {
+    "type": "object",
+    "required": [
+      "filename",
+      "content"
+    ],
+    "properties": {
+      "content": {
+        "type": "string",
+        "description": "Content for simple single-file gist creation"
+      },
+      "description": {
+        "type": "string",
+        "description": "Description of the gist"
+      },
+      "filename": {
+        "type": "string",
+        "description": "Filename for simple single-file gist creation"
+      },
+      "public": {
+        "type": "boolean",
+        "description": "Whether the gist is public",
+        "default": false
+      }
+    }
+  },
+  "name": "create_gist"
+}

pkg/github/__toolsnaps__/get_gist.snap

@@ -0,0 +1,20 @@
+{
+  "annotations": {
+    "readOnlyHint": true,
+    "title": "Get Gist Content"
+  },
+  "description": "Get gist content of a particular gist, by gist ID",
+  "inputSchema": {
+    "type": "object",
+    "required": [
+      "gist_id"
+    ],
+    "properties": {
+      "gist_id": {
+        "type": "string",
+        "description": "The ID of the gist"
+      }
+    }
+  },
+  "name": "get_gist"
+}

pkg/github/__toolsnaps__/list_gists.snap

@@ -0,0 +1,32 @@
+{
+  "annotations": {
+    "readOnlyHint": true,
+    "title": "List Gists"
+  },
+  "description": "List gists for a user",
+  "inputSchema": {
+    "type": "object",
+    "properties": {
+      "page": {
+        "type": "Number",
+        "description": "Page number for pagination (min 1)",
+        "minimum": 1
+      },
+      "perPage": {
+        "type": "Number",
+        "description": "Results per page for pagination (min 1, max 100)",
+        "minimum": 1,
+        "maximum": 100
+      },
+      "since": {
+        "type": "string",
+        "description": "Only gists updated after this time (ISO 8601 timestamp)"
+      },
+      "username": {
+        "type": "string",
+        "description": "GitHub username (omit for authenticated user's gists)"
+      }
+    }
+  },
+  "name": "list_gists"
+}

pkg/github/__toolsnaps__/update_gist.snap

@@ -0,0 +1,33 @@
+{
+  "annotations": {
+    "title": "Update Gist"
+  },
+  "description": "Update an existing gist",
+  "inputSchema": {
+    "type": "object",
+    "required": [
+      "gist_id",
+      "filename",
+      "content"
+    ],
+    "properties": {
+      "content": {
+        "type": "string",
+        "description": "Content for the file"
+      },
+      "description": {
+        "type": "string",
+        "description": "Updated description of the gist"
+      },
+      "filename": {
+        "type": "string",
+        "description": "Filename to update or create"
+      },
+      "gist_id": {
+        "type": "string",
+        "description": "ID of the gist to update"
+      }
+    }
+  },
+  "name": "update_gist"
+}