feat: Replace cookiecutter with built-in MiniJinja templating

- Add MiniJinja dependency for Jinja2-compatible templating
- Create new project_template.rs module for template rendering
- Bundle snowflake template in templates/snowflake/ directory
- Remove dependency on external cookiecutter Python tool
- Handle Gitea publishing natively in Rust instead of Python hooks
- Update default template path to use bundled template with fallback
- Update README to reflect new built-in templating
- All tests pass

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

templates/snowflake/create_structure.sh

@@ -0,0 +1,84 @@
+#!/usr/bin/env bash
+#
+# create_snowflake_structure.sh
+# -------------------------------------------------
+# Creates a ready‑to‑use folder layout for the Snowflake
+# writing outline method.
+#
+# Usage:
+#   ./create_snowflake_structure.sh "MyNovel"
+#
+# If no argument is supplied, the script defaults to a folder
+# named "SnowflakeProject".
+# -------------------------------------------------
+
+set -euo pipefail   # safety: exit on error, treat unset vars as errors
+
+# ------------------------------------------------------------------
+# Helper: print a short usage message
+# ------------------------------------------------------------------
+usage() {
+    echo "Usage: $0 [project_folder_name]"
+    echo "Creates the Snowflake writing‑method folder structure."
+    exit 1
+}
+
+# ------------------------------------------------------------------
+# Determine the root folder name
+# ------------------------------------------------------------------
+PROJECT_NAME="${1:-SnowflakeProject}"
+ROOT_DIR="${PWD}/${PROJECT_NAME}"
+
+# ------------------------------------------------------------------
+# Define the directory tree (relative to ROOT_DIR)
+# ------------------------------------------------------------------
+DIRS=(
+    "01-Premise"
+    "02-Synopsis"
+    "03-Characters/main_characters"
+    "03-Characters/supporting_characters"
+    "03-Characters/character_grid"
+    "04-PlotOutline"
+    "04-PlotOutline/scene_breakdown"
+    "05-NarrativeSheets/act_1"
+    "05-NarrativeSheets/act_2"
+    "05-NarrativeSheets/act_3"
+    "06-FirstDraft"
+    "07-Revisions/structural_edits"
+    "07-Revisions/line_edits"
+    "07-Revisions/proofreading"
+    "08-Final/metadata"
+    "08-Final/submission_materials"
+)
+
+# ------------------------------------------------------------------
+# Create the directories
+# ------------------------------------------------------------------
+echo "Creating project folder: ${ROOT_DIR}"
+mkdir -p "${ROOT_DIR}"
+
+for d in "${DIRS[@]}"; do
+    mkdir -p "${ROOT_DIR}/${d}"
+done
+
+# ------------------------------------------------------------------
+# Optional: create placeholder files so you have a starting point
+# ------------------------------------------------------------------
+touch "${ROOT_DIR}/01-Premise/premise.txt"
+touch "${ROOT_DIR}/02-Synopsis/synopsis.txt"
+touch "${ROOT_DIR}/03-Characters/main_characters/protagonist.md"
+touch "${ROOT_DIR}/03-Characters/main_characters/antagonist.md"
+touch "${ROOT_DIR}/03-Characters/character_grid/character_grid.xlsx"
+touch "${ROOT_DIR}/04-PlotOutline/plot_outline.docx"
+touch "${ROOT_DIR}/05-NarrativeSheets/act_1/scene_01.md"
+touch "${ROOT_DIR}/06-FirstDraft/draft_v1.docx"
+touch "${ROOT_DIR}/07-Revisions/structural_edits/notes.txt"
+touch "${ROOT_DIR}/08-Final/final_manuscript.docx"
+touch "${ROOT_DIR}/README.md"
+
+# ------------------------------------------------------------------
+# Finished
+# ------------------------------------------------------------------
+echo "Folder structure created successfully!"
+echo "Root directory: ${ROOT_DIR}"
+echo "You can now start populating the files."