feat(cli): omnigraph config migrate — the RFC-008 split (stage 2)

Reads a legacy omnigraph.yaml and produces the three-section split: team
half as a ready-to-review cluster.yaml proposal (graphs with TODO schema
pointers — the legacy file never knew schemas — per-graph queries
directories, policies with applies_to bindings), personal half as an
operator-config merge (actor, output/table defaults — OperatorDefaults
gains the two table keys with their cascade hops — remote graphs with
bearer_token_env become servers entries plus a printed login step, and
legacy aliases split per the RFC: content to the catalog as a manual
step, binding to an operator alias), plus a dropped-keys section with
reasons. Touches nothing without --write; with it, the operator merge is
key-level (existing entries always win; prior file backed up), and
cluster.yaml is emitted only when absent (else cluster.yaml.proposed).
--json emits the report structurally.

The completeness contract is a unit test: every top-level key of the
legacy schema must classify somewhere, or the RFC-008 map has a bug.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/omnigraph-cli/src/operator.rs

@@ -91,6 +91,10 @@ pub(crate) struct OperatorIdentity {
 pub(crate) struct OperatorDefaults {
     /// Default read output format, below every more-specific source.
     pub(crate) output: Option<ReadOutputFormat>,
+    /// Table rendering preferences (below the legacy cli.table_* keys
+    /// during the RFC-008 window).
+    pub(crate) table_max_column_width: Option<usize>,
+    pub(crate) table_cell_layout: Option<omnigraph_server::config::TableCellLayout>,
     #[serde(flatten)]
     unknown: serde_yaml::Mapping,
 }