feat(cli): add template generation commands

- Introduces `gen` subcommand for HDL template generation
- Adds Jinja2 dependency for template rendering
- Updates project model to support template configurations
- Implements template listing and rendering functionality

pyproject.toml

@@ -18,6 +18,7 @@ pydantic = "^2.11.3"
 rich = "^14.0.0"
 gitpython = "^3.1.44"
 typer = "^0.16.0"
+jinja2 = "^3.1.6"
 
 [tool.poetry.group.dev.dependencies]
 twine = "^6.1.0"

src/hdlbuild/cli.py

@@ -1,6 +1,7 @@
 import typer
 from importlib.metadata import version, PackageNotFoundError
 
+from hdlbuild.commands.gen import cli as gen_cli
 from hdlbuild.commands.build import cli as build_cli
 from hdlbuild.commands.clean import cli as clean_cli
 from hdlbuild.commands.dep   import cli as dep_cli
@@ -18,12 +19,12 @@ app = typer.Typer(
     help=f"hdlbuild v{get_version()} – Build‑Management for FPGA projects"
 )
 
-# Unter‑Kommandos registrieren (entspricht add_subparsers)
 app.add_typer(build_cli, name="build", help="Build the project")
 app.add_typer(clean_cli, name="clean", help="Clean build artifacts")
 app.add_typer(dep_cli,   name="dep",   help="Resolve dependencies")
 app.add_typer(test_cli,  name="test",  help="Run simulations/testbenches")
 app.add_typer(init_cli,  name="init",  help="Initialize project")
+app.add_typer(gen_cli,   name="gen",   help="Generate HDL files from templates")
 
 def main():
     app()

src/hdlbuild/commands/gen.py

@@ -0,0 +1,53 @@
+from __future__ import annotations
+
+import typer
+
+from hdlbuild.generate.template_generator import TemplateGenerator
+from hdlbuild.utils.console_utils import ConsoleUtils
+from hdlbuild.utils.project_loader import load_project_config
+
+cli = typer.Typer(rich_help_panel="🧬 Template Commands")
+
+@cli.command("list")
+def list_templates() -> None:
+    """
+    List all available template names from *project.yml*.
+
+    ```bash
+    hdlbuild gen list
+    ```
+    """
+    console = ConsoleUtils("hdlbuild")
+    project = load_project_config()
+    TemplateGenerator.list_templates(project, console)
+
+
+@cli.callback(invoke_without_command=True)
+def gen( 
+    ctx: typer.Context,
+    name: str = typer.Option(
+        None,
+        "--name",
+        "-n",
+        help="Name of the template to generate (from project.yml)",
+        show_default=False,
+    ),
+    dry_run: bool = typer.Option(
+        False,
+        "--dry-run",
+        help="Only show the output without writing file",
+    ),
+) -> None:
+    """
+    Render HDL files from Jinja2 templates.
+
+    * `hdlbuild gen` → render all templates  
+    * `hdlbuild gen <name>` → render a specific template  
+    * `hdlbuild gen <name> --dry-run` → only show output without saving
+    """
+    console = ConsoleUtils("hdlbuild")
+    project = load_project_config()
+
+    # Only executed when no subcommand (e.g., "list") is active.
+    if ctx.invoked_subcommand is None:
+        TemplateGenerator.generate(project, name, dry_run, console)

src/hdlbuild/generate/template_generator.py

@@ -0,0 +1,120 @@
+"""
+hdlbuild.generate.template_generator
+====================================
+
+Enthält die Klasse :class:`TemplateGenerator`, die das Auflisten und Rendern
+von in *project.yml* definierten Jinja2-Templates kapselt.
+"""
+
+from __future__ import annotations
+
+import os
+from typing import Optional
+
+from jinja2 import Environment, FileSystemLoader
+
+from hdlbuild.models.templates import TemplateInstance
+from hdlbuild.utils.console_utils import ConsoleUtils
+
+
+class TemplateGenerator:
+    """
+    Hilfsklasse zum Auflisten und Rendern der im Projekt konfigurierten
+    Jinja2-Templates.
+    """
+
+    # --------------------------------------------------------------------- #
+    # Öffentliche API
+    # --------------------------------------------------------------------- #
+
+    @staticmethod
+    def list_templates(project, console: ConsoleUtils) -> None:
+        """
+        Alle in *project.yml* definierten Templates auflisten.
+        """
+        if not project.templates:
+            console.print("[yellow]No templates defined in project.yml")
+            return
+
+        console.print("[bold underline]Available Templates:")
+        for name in project.templates.root.keys():
+            console.print(f"• {name}")
+
+    @classmethod
+    def generate(
+        cls,
+        project,
+        name: Optional[str],
+        dry_run: bool,
+        console: ConsoleUtils,
+    ) -> None:
+        """
+        Templates erzeugen.
+
+        Parameters
+        ----------
+        project
+            Geladenes Projekt-Model.
+        name
+            Name eines einzelnen Templates oder *None*, um alle Templates
+            zu erzeugen.
+        dry_run
+            Wenn *True*, wird das gerenderte Ergebnis nur ausgegeben,
+            jedoch nicht auf die Festplatte geschrieben.
+        console
+            Farbige Konsolen-Ausgaben.
+        """
+        if not project.templates:
+            console.print("[red]No templates defined in project.yml")
+            return
+
+        templates = project.templates.root
+
+        if name:
+            # Ein bestimmtes Template
+            if name not in templates:
+                console.print(f"[red]Template '{name}' not found.")
+                return
+            cls._render_template(name, templates[name], dry_run, console)
+        else:
+            # Alle Templates durchlaufen
+            for tname, template in templates.items():
+                cls._render_template(tname, template, dry_run, console)
+
+    # --------------------------------------------------------------------- #
+    # Interne Helfer
+    # --------------------------------------------------------------------- #
+
+    @staticmethod
+    def _render_template(
+        name: str,
+        template: TemplateInstance,
+        dry_run: bool,
+        console: ConsoleUtils,
+    ) -> None:
+        """
+        Einzelnes Template rendern und wahlweise speichern.
+        """
+        template_path = template.template
+        output_path = template.output
+        variables = template.variables
+
+        env = Environment(
+            loader=FileSystemLoader(os.path.dirname(template_path)),
+            trim_blocks=True,
+            lstrip_blocks=True,
+        )
+        j2 = env.get_template(os.path.basename(template_path))
+        result = j2.render(**variables)
+
+        if dry_run:
+            console.print(f"[green]--- Template: {name} (dry-run) ---")
+            console.print(result)
+            console.print(f"[green]--- End of {name} ---")
+            return
+
+        os.makedirs(os.path.dirname(output_path), exist_ok=True)
+        with open(output_path, "w") as f:
+            f.write(result)
+
+        console.print(f"[cyan]✔ Rendered template '{name}' → {output_path}")

src/hdlbuild/models/project.py

@@ -1,6 +1,8 @@
 from pydantic import BaseModel, Field
 from typing import List, Optional
 
+from hdlbuild.models.templates import ProjectTemplates
+
 class SourceFile(BaseModel):
     path: str
     library: str = "work"   # Default auf 'work'
@@ -43,6 +45,7 @@ class ProjectConfig(BaseModel):
     sources: Sources
     testbenches: Optional[Testbenches] = None
     constraints: Optional[str] = None
+    templates: Optional[ProjectTemplates] = None
     build: Optional[BuildOptions] = None
     dependencies: Optional[List[Dependency]] = Field(default_factory=list)
     tool_options: Optional[ToolOptions] = ToolOptions()

src/hdlbuild/models/templates.py

@@ -0,0 +1,14 @@
+from pydantic import BaseModel, Field, RootModel
+from typing import Dict, Any
+
+class TemplateInstance(BaseModel):
+    template: str                       # Pfad zur Jinja2-Vorlage
+    output: str                         # Zielpfad
+    variables: Dict[str, Any] = Field(default_factory=dict)  # Variablen für Rendering
+
+class ProjectTemplates(RootModel):
+    """
+    Pydantic-RootModel, das die Mapping-Struktur *name → TemplateInstance*
+    kapselt.  In Pydantic v2 ersetzt `RootModel` die frühere `__root__`-Syntax.
+    """
+    root: Dict[str, TemplateInstance]  # key = Name wie „alu“, „control_unit“