feat: add create_project and create_iteration_field methods to projects_write

Add two new methods to the consolidated projects_write tool:

- create_project: creates a new GitHub ProjectsV2 for a user or org
- create_iteration_field: adds an iteration field to a project with
  configurable sprint duration and start date

Key design decisions:
- Consolidated into projects_write following existing projects pattern
  (projects_list, projects_get, projects_write all use method dispatch)
- iterations parameter is optional (basic field config uses just
  start_date and duration; named iterations are a power-user option)
- project_number made conditionally required (not needed for
  create_project; validated per-method in handler)
- owner_type auto-detection works for create_iteration_field;
  required for create_project (no project to detect from)
- Fixed gosec G115 int overflow with explicit int32 casts

Closes #1854

Co-authored-by: João Doria de Souza <hi@joao.work>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 3 people

README.md

@@ -1014,22 +1014,26 @@ The following sets of tools are available:
   - `project_number`: The project's number. Required for 'list_project_fields', 'list_project_items', and 'list_project_status_updates' methods. (number, optional)
   - `query`: Filter/query string. For list_projects: filter by title text and state (e.g. "roadmap is:open"). For list_project_items: advanced filtering using GitHub's project filtering syntax. (string, optional)
 
-- **projects_write** - Modify GitHub Project items
+- **projects_write** - Manage GitHub Projects
   - **Required OAuth Scopes**: `project`
   - `body`: The body of the status update (markdown). Used for 'create_project_status_update' method. (string, optional)
+  - `duration`: Duration in days for each iteration (e.g. 7 for weekly, 14 for bi-weekly). Required for 'create_iteration_field' method. (number, optional)
+  - `field_name`: The name of the iteration field (e.g. 'Sprint'). Required for 'create_iteration_field' method. (string, optional)
   - `issue_number`: The issue number (use when item_type is 'issue' for 'add_project_item' method). Provide either issue_number or pull_request_number. (number, optional)
   - `item_id`: The project item ID. Required for 'update_project_item' and 'delete_project_item' methods. (number, optional)
   - `item_owner`: The owner (user or organization) of the repository containing the issue or pull request. Required for 'add_project_item' method. (string, optional)
   - `item_repo`: The name of the repository containing the issue or pull request. Required for 'add_project_item' method. (string, optional)
   - `item_type`: The item's type, either issue or pull_request. Required for 'add_project_item' method. (string, optional)
+  - `iterations`: Optional array of iteration definitions for 'create_iteration_field' method. Each entry defines a named iteration with a start date and duration. If omitted, the field is created with default iteration settings. (object[], optional)
   - `method`: The method to execute (string, required)
   - `owner`: The project owner (user or organization login). The name is not case sensitive. (string, required)
-  - `owner_type`: Owner type (user or org). If not provided, will be automatically detected. (string, optional)
-  - `project_number`: The project's number. (number, required)
+  - `owner_type`: Owner type (user or org). Required for 'create_project' method. If not provided for other methods, will be automatically detected. (string, optional)
+  - `project_number`: The project's number. Required for all methods except 'create_project'. (number, optional)
   - `pull_request_number`: The pull request number (use when item_type is 'pull_request' for 'add_project_item' method). Provide either issue_number or pull_request_number. (number, optional)
-  - `start_date`: The start date of the status update in YYYY-MM-DD format. Used for 'create_project_status_update' method. (string, optional)
+  - `start_date`: Start date in YYYY-MM-DD format. Used for 'create_project_status_update' and 'create_iteration_field' methods. (string, optional)
   - `status`: The status of the project. Used for 'create_project_status_update' method. (string, optional)
   - `target_date`: The target date of the status update in YYYY-MM-DD format. Used for 'create_project_status_update' method. (string, optional)
+  - `title`: The project title. Required for 'create_project' method. (string, optional)
   - `updated_field`: Object consisting of the ID of the project field to update and the new value for the field. To clear the field, set value to null. Example: {"id": 123456, "value": "New Value"}. Required for 'update_project_item' method. (object, optional)
 
 </details>

pkg/github/__toolsnaps__/projects_write.snap

@@ -1,15 +1,23 @@
 {
   "annotations": {
     "destructiveHint": true,
-    "title": "Modify GitHub Project items"
+    "title": "Manage GitHub Projects"
   },
-  "description": "Add, update, or delete project items, or create status updates in a GitHub Project.",
+  "description": "Create and manage GitHub Projects: create projects, add/update/delete items, create status updates, and add iteration fields.",
   "inputSchema": {
     "properties": {
       "body": {
         "description": "The body of the status update (markdown). Used for 'create_project_status_update' method.",
         "type": "string"
       },
+      "duration": {
+        "description": "Duration in days for each iteration (e.g. 7 for weekly, 14 for bi-weekly). Required for 'create_iteration_field' method.",
+        "type": "number"
+      },
+      "field_name": {
+        "description": "The name of the iteration field (e.g. 'Sprint'). Required for 'create_iteration_field' method.",
+        "type": "string"
+      },
       "issue_number": {
         "description": "The issue number (use when item_type is 'issue' for 'add_project_item' method). Provide either issue_number or pull_request_number.",
         "type": "number"
@@ -34,13 +42,41 @@
         ],
         "type": "string"
       },
+      "iterations": {
+        "description": "Optional array of iteration definitions for 'create_iteration_field' method. Each entry defines a named iteration with a start date and duration. If omitted, the field is created with default iteration settings.",
+        "items": {
+          "properties": {
+            "duration": {
+              "description": "Duration in days",
+              "type": "number"
+            },
+            "startDate": {
+              "description": "Start date in YYYY-MM-DD format",
+              "type": "string"
+            },
+            "title": {
+              "description": "Iteration title (e.g. 'Sprint 1')",
+              "type": "string"
+            }
+          },
+          "required": [
+            "title",
+            "startDate",
+            "duration"
+          ],
+          "type": "object"
+        },
+        "type": "array"
+      },
       "method": {
         "description": "The method to execute",
         "enum": [
           "add_project_item",
           "update_project_item",
           "delete_project_item",
-          "create_project_status_update"
+          "create_project_status_update",
+          "create_project",
+          "create_iteration_field"
         ],
         "type": "string"
       },
@@ -49,23 +85,23 @@
         "type": "string"
       },
       "owner_type": {
-        "description": "Owner type (user or org). If not provided, will be automatically detected.",
+        "description": "Owner type (user or org). Required for 'create_project' method. If not provided for other methods, will be automatically detected.",
         "enum": [
           "user",
           "org"
         ],
         "type": "string"
       },
       "project_number": {
-        "description": "The project's number.",
+        "description": "The project's number. Required for all methods except 'create_project'.",
         "type": "number"
       },
       "pull_request_number": {
         "description": "The pull request number (use when item_type is 'pull_request' for 'add_project_item' method). Provide either issue_number or pull_request_number.",
         "type": "number"
       },
       "start_date": {
-        "description": "The start date of the status update in YYYY-MM-DD format. Used for 'create_project_status_update' method.",
+        "description": "Start date in YYYY-MM-DD format. Used for 'create_project_status_update' and 'create_iteration_field' methods.",
         "type": "string"
       },
       "status": {
@@ -83,15 +119,18 @@
         "description": "The target date of the status update in YYYY-MM-DD format. Used for 'create_project_status_update' method.",
         "type": "string"
       },
+      "title": {
+        "description": "The project title. Required for 'create_project' method.",
+        "type": "string"
+      },
       "updated_field": {
         "description": "Object consisting of the ID of the project field to update and the new value for the field. To clear the field, set value to null. Example: {\"id\": 123456, \"value\": \"New Value\"}. Required for 'update_project_item' method.",
         "type": "object"
       }
     },
     "required": [
       "method",
-      "owner",
-      "project_number"
+      "owner"
     ],
     "type": "object"
   },