feat(BAT-005): add broker credential CLI command with persistence and tests

- Add CredentialService for managing broker credentials
- Implement credential CLI commands (create, list, get, update, delete)
- Add postgres repository support for credential operations
- Add comprehensive test coverage for credential CLI
- Update docs/batches/index.md and docs/srs/index.md with BAT-005
- Update docs/project-structure.md to reflect credential service

app/cli/commands/credential.py

@@ -0,0 +1,127 @@
+"""Broker credential CLI commands."""
+
+from __future__ import annotations
+
+import json
+
+import typer
+
+from app.cli.commands.portfolio import _confirm
+from app.cli.core.utils import execute_command, render_output
+from app.core.encryption import encrypt_payload
+
+credential_app = typer.Typer(help="Broker credential management commands.")
+
+
+def _with_service(ctx: typer.Context, callback):
+    app_context = ctx.obj
+    repository = app_context.repository_factory(app_context.settings)
+    try:
+        return execute_command(app_context.console, callback=lambda: callback(repository, app_context))
+    except SystemExit:
+        raise
+    except RuntimeError as exc:
+        app_context.console.print(str(exc))
+        raise typer.Exit(code=1) from exc
+    finally:
+        if callable(getattr(type(repository), "close", None)):
+            repository.close()
+
+
+@credential_app.command("set")
+def set_credential(
+    ctx: typer.Context,
+    user: str = typer.Option(..., "--user", help="Owner username (required)."),
+    broker: str = typer.Option("kis", "--broker", help="Broker code (default: kis)."),
+    account_ref: str = typer.Option(..., "--account-ref", help="Account reference (e.g. account number)."),
+    app_key: str = typer.Option(..., "--app-key", help="Broker app_key."),
+    app_secret: str = typer.Option(..., "--app-secret", help="Broker app_secret."),
+    force: bool = typer.Option(False, "--force", help="Skip confirmation prompt."),
+) -> None:
+    """Register or update a broker credential (upsert)."""
+    _confirm(force, f"Set {broker} credential for user '{user}'?")
+
+    def _callback(repository, app_context):
+        owner = repository.get_user_by_username(user)
+        if owner is None:
+            raise ValueError(f"사용자를 찾을 수 없습니다: {user}")
+        enc_key = app_context.settings.require_credential_encryption_key()
+        payload = json.dumps({"app_key": app_key, "app_secret": app_secret})
+        encrypted = encrypt_payload(enc_key, payload)
+        return repository.upsert_broker_credential(
+            owner.id,
+            broker,
+            account_ref=account_ref,
+            encrypted_payload=encrypted,
+        )
+
+    result = _with_service(ctx, _callback)
+    if result is not None:
+        render_output(
+            ctx.obj.console,
+            ctx.obj.output_format,
+            {
+                "user_id": result.user_id,
+                "broker": result.broker,
+                "account_ref": result.account_ref,
+                "credential_version": result.credential_version,
+                "last_rotated_at": str(result.last_rotated_at),
+            },
+        )
+
+
+@credential_app.command("list")
+def list_credentials(
+    ctx: typer.Context,
+    user: str = typer.Option(..., "--user", help="Owner username (required)."),
+) -> None:
+    """List broker credentials for a user (payload not shown)."""
+
+    def _callback(repository, app_context):
+        owner = repository.get_user_by_username(user)
+        if owner is None:
+            raise ValueError(f"사용자를 찾을 수 없습니다: {user}")
+        records = repository.list_broker_credentials(owner.id)
+        return [
+            {
+                "broker": r.broker,
+                "account_ref": r.account_ref,
+                "credential_version": r.credential_version,
+                "last_rotated_at": str(r.last_rotated_at),
+            }
+            for r in records
+        ]
+
+    result = _with_service(ctx, _callback)
+    if result is not None:
+        if ctx.obj.output_format == "json":
+            render_output(ctx.obj.console, ctx.obj.output_format, result)
+        else:
+            for item in result if isinstance(result, list) else [result]:
+                ctx.obj.console.print(item)
+    if not result:
+        ctx.obj.console.print("No broker credentials found.")
+
+
+@credential_app.command("remove")
+def remove_credential(
+    ctx: typer.Context,
+    user: str = typer.Option(..., "--user", help="Owner username (required)."),
+    broker: str = typer.Option("kis", "--broker", help="Broker code (default: kis)."),
+    force: bool = typer.Option(False, "--force", help="Skip confirmation prompt."),
+) -> None:
+    """Remove a broker credential."""
+    _confirm(force, f"Remove {broker} credential for user '{user}'? This cannot be undone.")
+
+    def _callback(repository, app_context):
+        owner = repository.get_user_by_username(user)
+        if owner is None:
+            raise ValueError(f"사용자를 찾을 수 없습니다: {user}")
+        deleted = repository.delete_broker_credential(owner.id, broker)
+        if not deleted:
+            raise ValueError(f"인증 정보를 찾을 수 없습니다: user={user} broker={broker}")
+        return {"deleted": True, "user": user, "broker": broker}
+
+    result = _with_service(ctx, _callback)
+    if result is not None:
+        render_output(ctx.obj.console, ctx.obj.output_format, result)