Polish schema endpoint: rename show, align field name, add tests

Review feedback on #23, applied on top of the original commit:

- Rename the CLI subcommand from `schema get` to `schema show` to match
  the existing `run show` / `commit show` convention. A `#[command(alias
  = "get")]` preserves muscle memory for anyone who already typed `get`.
- Rename `SchemaGetOutput` → `SchemaOutput` and its field `source` →
  `schema_source`, so the get response and the apply request use the
  same field name for the same concept.
- Use `println!` instead of `print!` in the CLI so the shell prompt
  doesn't land on the last line of schema output.
- Add three integration tests on `/schema`: happy path (no auth),
  401 when bearer is required but missing, 403 when the policy grants
  the actor branch_create but not read.

Follow-ups left for a separate PR: include `schema_ir_hash` and
`schema_identity_version` in the response payload so clients can do
drift detection and the server can set an ETag; and a fast-path local
read that skips `Omnigraph::open()` when only the schema source is
needed.

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

crates/omnigraph-server/src/api.rs

@@ -281,8 +281,8 @@ pub struct SchemaApplyOutput {
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]
-pub struct SchemaGetOutput {
-    pub source: String,
+pub struct SchemaOutput {
+    pub schema_source: String,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]

crates/omnigraph-server/src/lib.rs

@@ -14,7 +14,7 @@ use api::{
     BranchMergeOutput, BranchMergeRequest, ChangeOutput, ChangeRequest, CommitListOutput,
     CommitListQuery, ErrorCode, ErrorOutput, ExportRequest, HealthOutput, IngestOutput,
     IngestRequest, ReadOutput, ReadRequest, RunListOutput, SchemaApplyOutput, SchemaApplyRequest,
-    SchemaGetOutput, SnapshotQuery, ingest_output, schema_apply_output, snapshot_payload,
+    SchemaOutput, SnapshotQuery, ingest_output, schema_apply_output, snapshot_payload,
 };
 use axum::body::{Body, Bytes};
 use axum::extract::DefaultBodyLimit;
@@ -803,7 +803,7 @@ async fn server_change(
     path = "/schema",
     tag = "schema",
     responses(
-        (status = 200, description = "Current schema source", body = SchemaGetOutput),
+        (status = 200, description = "Current schema source", body = SchemaOutput),
         (status = 401, description = "Unauthorized", body = ErrorOutput),
         (status = 403, description = "Forbidden", body = ErrorOutput),
     ),
@@ -812,7 +812,7 @@ async fn server_change(
 async fn server_schema_get(
     State(state): State<AppState>,
     actor: Option<Extension<AuthenticatedActor>>,
-) -> std::result::Result<Json<SchemaGetOutput>, ApiError> {
+) -> std::result::Result<Json<SchemaOutput>, ApiError> {
     authorize_request(
         &state,
         actor.as_ref().map(|Extension(actor)| actor),
@@ -826,11 +826,11 @@ async fn server_schema_get(
             target_branch: None,
         },
     )?;
-    let source = {
+    let schema_source = {
         let db = Arc::clone(&state.db).read_owned().await;
         db.schema_source().to_string()
     };
-    Ok(Json(SchemaGetOutput { source }))
+    Ok(Json(SchemaOutput { schema_source }))
 }
 
 #[utoipa::path(