feat: generate implementation plan and design artifacts

.gemini/commands/specify.toml

@@ -0,0 +1,17 @@
+description = "Create or update the feature specification from a natural language feature description."
+
+prompt = """
+---
+description: Create or update the feature specification from a natural language feature description.
+---
+
+Given the feature description provided as an argument, do this:
+
+1. Run the script `.specify/scripts/bash/create-new-feature.sh --json "{{args}}"` from repo root and parse its JSON output for BRANCH_NAME and SPEC_FILE. All file paths must be absolute.
+  **IMPORTANT** You must only ever run this script once. The JSON is provided in the terminal as output - always refer to it to get the actual content you're looking for.
+2. Load `.specify/templates/spec-template.md` to understand required sections.
+3. Write the specification to SPEC_FILE using the template structure, replacing placeholders with concrete details derived from the feature description (arguments) while preserving section order and headings.
+4. Report completion with branch name, spec file path, and readiness for the next phase.
+
+Note: The script creates and checks out the new branch and initializes the spec file before writing.
+"""