Replace docker compose with persistent per-project lifecycle

Move from docker compose run to a Python-managed container lifecycle.
Each project now gets a dedicated container that is started on demand
and stopped when opencode exits, instead of being recreated each time.

Use a shared home directory across projects so configurations presist.

The container are not destroyed, so tools and caches can be installed
specifically for a project by opencode itself once and reused, while
still avoiding long-running containers.

opencode-container.py

@@ -0,0 +1,161 @@
+#!/usr/bin/env python3
+
+import hashlib
+import os
+import subprocess
+import sys
+import time
+from pathlib import Path
+
+
+class OpenCodeContainer:
+    IMAGE = "opencode-container:latest"
+    PROJECT_ID_LEN = 12
+    START_TIMEOUT = 3.0
+
+    def __init__(self):
+        self.project_path = Path.cwd().resolve()
+        self.project_id = self._project_id(self.project_path)
+        self.container_name = f"oc-{self.project_path.name}-{self.project_id}"
+        self.docker_context_dir = Path(__file__).resolve().parent
+
+    # =========================
+    # Public entrypoint
+    # =========================
+
+    def run(self, args: list[str]) -> None:
+        if not self.image_exists():
+            self.build_image()
+
+        if not self.container_exists():
+            self.create_container()
+
+        if not self.start_container():
+            print("Recreating container due to failed start")
+            self.remove_container()
+            self.create_container()
+            if not self.start_container():
+                raise RuntimeError("Container failed to start after recreation")
+
+        try:
+            self.exec_opencode(args)
+        finally:
+            self.stop_container()
+
+    # =========================
+    # Image handling
+    # =========================
+
+    def image_exists(self) -> bool:
+        return subprocess.run(
+            ["docker", "image", "inspect", self.IMAGE],
+            stdout=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL,
+        ).returncode == 0
+
+    def build_image(self) -> None:
+        print(f"Building image '{self.IMAGE}'")
+        self._run([
+            "docker", "build",
+            "-t", self.IMAGE,
+            str(self.docker_context_dir),
+        ])
+
+    # =========================
+    # Container lifecycle
+    # =========================
+
+    def create_container(self) -> None:
+        uid = os.getuid()
+        gid = os.getgid()
+
+        print(f"Creating container '{self.container_name}'")
+
+        self._run([
+            "docker", "create",
+            "--name", self.container_name,
+            "--user", f"{uid}:{gid}",
+            "--volume", f"{self.project_path}:{self.project_path}",
+            self.IMAGE,
+            "sh", "-c", "sleep infinity",
+        ])
+
+    def start_container(self) -> bool:
+        subprocess.run(
+            ["docker", "start", self.container_name],
+            stdout=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL,
+        )
+        return self.wait_until_running()
+
+    def stop_container(self) -> None:
+        if self.container_running():
+            self._run(["docker", "stop", "-t", "0", self.container_name])
+
+    def remove_container(self) -> None:
+        subprocess.run(
+            ["docker", "rm", "-f", self.container_name],
+            stdout=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL,
+        )
+
+    # =========================
+    # Execution
+    # =========================
+
+    def exec_opencode(self, args: list[str]) -> None:
+        subprocess.run([
+            "docker", "exec",
+            "-it",
+            "-w", str(self.project_path),
+            self.container_name,
+            "opencode",
+            *args,
+        ], check=True)
+
+    # =========================
+    # State checks
+    # =========================
+
+    def container_exists(self) -> bool:
+        return subprocess.run(
+            ["docker", "inspect", self.container_name],
+            stdout=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL,
+        ).returncode == 0
+
+    def container_running(self) -> bool:
+        result = subprocess.run(
+            ["docker", "inspect", "-f", "{{.State.Running}}", self.container_name],
+            capture_output=True,
+            text=True,
+        )
+        return result.returncode == 0 and result.stdout.strip() == "true"
+
+    def wait_until_running(self) -> bool:
+        deadline = time.time() + self.START_TIMEOUT
+        while time.time() < deadline:
+            if self.container_running():
+                return True
+            time.sleep(0.1)
+        return False
+
+    # =========================
+    # Helpers
+    # =========================
+
+    @staticmethod
+    def _project_id(path: Path) -> str:
+        return hashlib.sha256(str(path).encode()).hexdigest()[:12]
+
+    @staticmethod
+    def _run(cmd: list[str]) -> None:
+        subprocess.run(cmd, check=True)
+
+
+def main() -> None:
+    OpenCodeContainer().run(sys.argv[1:])
+
+
+if __name__ == "__main__":
+    main()