feat(manager-core,picloud): per-handler require(capability) checks

Every admin endpoint now resolves Capability for the loaded resource
and calls authz::require(...) before mutating. Forbidden → 403; every
handler State carries an Arc<dyn AuthzRepo>, plumbed from the new
PostgresAppMembersRepository in the picloud binary.

* api.rs (scripts): AppRead/AppWriteScript/AppLogRead bound to
  script.app_id after load. List branches on instance_role:
  Member → list_for_user, others → list (or ?app= filtered).
* apps_api.rs: InstanceCreateApp on POST; AppRead on get/list_domains;
  AppAdmin on patch/delete/slug:check; AppManageDomains on
  create_domain/delete_domain. list_apps membership-filters for Member.
* admin_users_api.rs: InstanceManageUsers on every endpoint. Mint +
  PATCH refuse to grant Owner unless the caller is already Owner
  (CannotEscalate / 422), on top of the existing last-owner guard.
* route_admin.rs: AppRead on list/check/match; AppWriteRoute on
  create/delete bound to the route's actual app_id (added a
  RouteRepository::get(uuid) lookup so delete binds correctly).
* AppRepository + ScriptRepository gain list_for_user(user_id) for
  membership-filtered listings.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/manager-core/src/admin_users_api.rs

@@ -14,18 +14,17 @@ use axum::extract::{Path, State};
 use axum::http::StatusCode;
 use axum::response::{IntoResponse, Json, Response};
 use axum::routing::get;
-use axum::Router;
+use axum::{Extension, Router};
 use chrono::{DateTime, Utc};
-use picloud_shared::AdminUserId;
+use picloud_shared::{AdminUserId, InstanceRole, Principal};
 use serde::{Deserialize, Serialize};
 use serde_json::json;
 
-use picloud_shared::InstanceRole;
-
 use crate::admin_session_repo::AdminSessionRepository;
 use crate::admin_user_repo::{AdminUserRepository, AdminUserRepositoryError, AdminUserRow};
 use crate::api_key_repo::ApiKeyRepository;
 use crate::auth::hash_password;
+use crate::authz::{require, AuthzDenied, AuthzRepo, Capability};
 
 /// Validation knobs are tuned by NIST 800-63B-ish guidance: username is
 /// a strict ASCII subset so the lookup column stays predictable, and
@@ -43,6 +42,9 @@ pub struct AdminsState {
     /// also expires every active API key for that user so cookie and
     /// bearer credentials become inert at the same moment.
     pub keys: Arc<dyn ApiKeyRepository>,
+    /// Capability gate: every endpoint here requires
+    /// `InstanceManageUsers` (owner / admin).
+    pub authz: Arc<dyn AuthzRepo>,
 }
 
 pub fn admins_router(state: AdminsState) -> Router {
@@ -113,15 +115,29 @@ pub struct PatchAdminRequest {
 
 async fn list_admins(
     State(state): State<AdminsState>,
+    Extension(principal): Extension<Principal>,
 ) -> Result<Json<Vec<AdminDto>>, AdminApiError> {
+    require(
+        state.authz.as_ref(),
+        &principal,
+        Capability::InstanceManageUsers,
+    )
+    .await?;
     let rows = state.users.list().await?;
     Ok(Json(rows.into_iter().map(Into::into).collect()))
 }
 
 async fn get_admin(
     State(state): State<AdminsState>,
+    Extension(principal): Extension<Principal>,
     Path(id): Path<AdminUserId>,
 ) -> Result<Json<AdminDto>, AdminApiError> {
+    require(
+        state.authz.as_ref(),
+        &principal,
+        Capability::InstanceManageUsers,
+    )
+    .await?;
     state
         .users
         .get(id)
@@ -133,8 +149,24 @@ async fn get_admin(
 
 async fn create_admin(
     State(state): State<AdminsState>,
+    Extension(principal): Extension<Principal>,
     Json(input): Json<CreateAdminRequest>,
 ) -> Result<(StatusCode, Json<AdminDto>), AdminApiError> {
+    require(
+        state.authz.as_ref(),
+        &principal,
+        Capability::InstanceManageUsers,
+    )
+    .await?;
+    // Minting an owner via the API requires the caller to ALSO be an
+    // owner — admin cannot self-elevate (or elevate someone else)
+    // beyond their own ceiling. Owner-creation by env-var bootstrap
+    // bypasses this path.
+    if input.instance_role == InstanceRole::Owner
+        && principal.instance_role != InstanceRole::Owner
+    {
+        return Err(AdminApiError::CannotEscalate);
+    }
     let username = input.username.trim();
     validate_username(username)?;
     validate_password(&input.password)?;
@@ -148,9 +180,16 @@ async fn create_admin(
 
 async fn patch_admin(
     State(state): State<AdminsState>,
+    Extension(principal): Extension<Principal>,
     Path(id): Path<AdminUserId>,
     Json(input): Json<PatchAdminRequest>,
 ) -> Result<Json<AdminDto>, AdminApiError> {
+    require(
+        state.authz.as_ref(),
+        &principal,
+        Capability::InstanceManageUsers,
+    )
+    .await?;
     // Verify the target exists upfront — keeps the error path uniform
     // for "rename a missing user" etc.
     let current = state
@@ -179,6 +218,12 @@ async fn patch_admin(
     }
 
     if let Some(new_role) = input.instance_role {
+        // Self-elevation guard: only an owner can promote anyone TO
+        // owner. An admin cannot turn themselves (or anyone else)
+        // into one.
+        if new_role == InstanceRole::Owner && principal.instance_role != InstanceRole::Owner {
+            return Err(AdminApiError::CannotEscalate);
+        }
         // Last-active-owner guard: a transition off of `Owner` cannot
         // leave the install with zero owners. The check is on the
         // source role (current.instance_role) so demoting an
@@ -249,8 +294,15 @@ async fn patch_admin(
 
 async fn delete_admin(
     State(state): State<AdminsState>,
+    Extension(principal): Extension<Principal>,
     Path(id): Path<AdminUserId>,
 ) -> Result<StatusCode, AdminApiError> {
+    require(
+        state.authz.as_ref(),
+        &principal,
+        Capability::InstanceManageUsers,
+    )
+    .await?;
     let target = state
         .users
         .get(id)
@@ -328,6 +380,15 @@ pub enum AdminApiError {
     #[error("cannot leave the system with zero active owners")]
     LastActiveOwner,
 
+    #[error("only an owner can grant the owner role")]
+    CannotEscalate,
+
+    #[error("forbidden")]
+    Forbidden,
+
+    #[error("authorization repo error: {0}")]
+    AuthzRepo(String),
+
     #[error("failed to hash password: {0}")]
     Hash(String),
 
@@ -335,6 +396,15 @@ pub enum AdminApiError {
     Repo(#[from] AdminUserRepositoryError),
 }
 
+impl From<AuthzDenied> for AdminApiError {
+    fn from(d: AuthzDenied) -> Self {
+        match d {
+            AuthzDenied::Denied => Self::Forbidden,
+            AuthzDenied::Repo(e) => Self::AuthzRepo(e.to_string()),
+        }
+    }
+}
+
 impl IntoResponse for AdminApiError {
     fn into_response(self) -> Response {
         let (status, message) = match &self {
@@ -347,9 +417,18 @@ impl IntoResponse for AdminApiError {
             | Self::InvalidPassword(_)
             | Self::LastActiveAdmin
             | Self::LastActiveOwner
+            | Self::CannotEscalate
             | Self::Repo(AdminUserRepositoryError::InvalidInstanceRole(_)) => {
                 (StatusCode::UNPROCESSABLE_ENTITY, self.to_string())
             }
+            Self::Forbidden => (StatusCode::FORBIDDEN, self.to_string()),
+            Self::AuthzRepo(e) => {
+                tracing::error!(error = %e, "admin_users authz error");
+                (
+                    StatusCode::INTERNAL_SERVER_ERROR,
+                    "internal error".to_string(),
+                )
+            }
             Self::Repo(AdminUserRepositoryError::NotFound(_)) => {
                 (StatusCode::NOT_FOUND, self.to_string())
             }