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/{{ cookiecutter.project_name }}/04-Outline/plot_outline.md

@@ -0,0 +1,35 @@
+<!-- The expanded outline (≈4 pages). -->
+
+## Act I – Setup (≈ 25 % of the story)
+
+<!-- Opening Image / Hook: A vivid snapshot of the protagonist’s ordinary world. Sets tone, setting, and the status‑quo the hero will soon leave. -->
+
+<!-- Inciting Incident: An event that disrupts the status‑quo and forces the protagonist to confront a problem. Creates the central conflict and gives the hero a reason to act. -->
+
+<!-- Key Event / Call to Adventure: The protagonist becomes aware of the stakes and is presented with a clear choice or challenge. Pushes the hero toward the journey; the point of no return begins to form. -->
+
+<!-- Debate / Refusal of the Call: The hero hesitates, doubts, or resists the upcoming change.  Highlights internal conflict and makes the eventual commitment feel earned. | -->
+
+<!-- Lock‑In / End of Act I: The hero decides to take action (or is forced into it). The story’s direction is now set. Marks the transition into the main confrontation; the protagonist is now “in the game.” -->
+
+## Act II – Confrontation (≈ 50 % of the story)
+
+<!-- First Plot Point: A decisive event propels the hero into a new world or situation (often a “point of no return”). Raises the stakes and moves the narrative firmly into the central conflict. -->
+
+<!-- Rising Action / Obstacles: Series of challenges, setbacks, and revelations that test the hero’s resolve. Builds tension, deepens character development, and expands the story’s scope. -->
+
+<!-- Midpoint: A major turning point—often a revelation, victory, or crisis—that changes the hero’s understanding or strategy. Re‑energizes the plot; the hero’s goal may shift or become clearer. -->
+
+<!-- Complications & Darkest Moment: Stakes intensify; the hero may suffer a major loss or face apparent defeat. Heightens emotional investment and sets up the need for a final push. -->
+
+<!-- Second Plot Point: The hero discovers a crucial piece of information or makes a decisive plan that leads to the climax. Provides the catalyst for the ultimate confrontation in Act III. -->
+
+## Act III – Resolution (≈ 25 % of the story)
+
+<!-- Climax: The highest‑stakes confrontation where the hero faces the central conflict head‑on. Delivers the story’s primary payoff; the outcome resolves the main tension. -->
+
+<!-- Falling Action: Immediate consequences of the climax unfold; loose ends begin to tie up.  Shows the impact of the climax on characters and world. -->
+
+<!-- Denouement / Resolution: Remaining subplots are resolved; the protagonist’s new equilibrium is shown. Gives closure, illustrating how the hero (and world) have changed. -->
+
+<!-- Final Image: A closing snapshot that mirrors (or contrasts) the opening image, highlighting transformation. Reinforces the thematic arc and leaves a lasting impression. -->

templates/snowflake/{{ cookiecutter.project_name }}/04-Outline/scene_breakdown/act_01.md

@@ -0,0 +1,11 @@
+## Act I – Setup (≈ 25 % of the story)
+
+<!-- Opening Image / Hook: A vivid snapshot of the protagonist’s ordinary world. Sets tone, setting, and the status‑quo the hero will soon leave. -->
+
+<!-- Inciting Incident: An event that disrupts the status‑quo and forces the protagonist to confront a problem. Creates the central conflict and gives the hero a reason to act. -->
+
+<!-- Key Event / Call to Adventure: The protagonist becomes aware of the stakes and is presented with a clear choice or challenge. Pushes the hero toward the journey; the point of no return begins to form. -->
+
+<!-- Debate / Refusal of the Call: The hero hesitates, doubts, or resists the upcoming change.  Highlights internal conflict and makes the eventual commitment feel earned. | -->
+
+<!-- Lock‑In / End of Act I: The hero decides to take action (or is forced into it). The story’s direction is now set. Marks the transition into the main confrontation; the protagonist is now “in the game.” -->

templates/snowflake/{{ cookiecutter.project_name }}/04-Outline/scene_breakdown/act_02.md

@@ -0,0 +1,11 @@
+## Act II – Confrontation (≈ 50 % of the story)
+
+<!-- First Plot Point: A decisive event propels the hero into a new world or situation (often a “point of no return”). Raises the stakes and moves the narrative firmly into the central conflict. -->
+
+<!-- Rising Action / Obstacles: Series of challenges, setbacks, and revelations that test the hero’s resolve. Builds tension, deepens character development, and expands the story’s scope. -->
+
+<!-- Midpoint: A major turning point—often a revelation, victory, or crisis—that changes the hero’s understanding or strategy. Re‑energizes the plot; the hero’s goal may shift or become clearer. -->
+
+<!-- Complications & Darkest Moment: Stakes intensify; the hero may suffer a major loss or face apparent defeat. Heightens emotional investment and sets up the need for a final push. -->
+
+<!-- Second Plot Point: The hero discovers a crucial piece of information or makes a decisive plan that leads to the climax. Provides the catalyst for the ultimate confrontation in Act III. -->

templates/snowflake/{{ cookiecutter.project_name }}/04-Outline/scene_breakdown/act_03.md

@@ -0,0 +1,9 @@
+## Act III – Resolution (≈ 25 % of the story)
+
+<!-- Climax: The highest‑stakes confrontation where the hero faces the central conflict head‑on. Delivers the story’s primary payoff; the outcome resolves the main tension. -->
+
+<!-- Falling Action: Immediate consequences of the climax unfold; loose ends begin to tie up.  Shows the impact of the climax on characters and world. -->
+
+<!-- Denouement / Resolution: Remaining subplots are resolved; the protagonist’s new equilibrium is shown. Gives closure, illustrating how the hero (and world) have changed. -->
+
+<!-- Final Image: A closing snapshot that mirrors (or contrasts) the opening image, highlighting transformation. Reinforces the thematic arc and leaves a lasting impression. -->