D3131 review: align Containers paper with reference impl; split std-c…

[pratzl]

…ontainer docs

D3131 Containers:

• Fix stale/incorrect names: edge_info -> edge_data, has_edge -> has_edges, edgelist namespace edgelist -> edge_list, edgelist CPOs to 2-arg f(el,e), override table vertices(g,u,pid) -> vertices(g,pid), partition_id(g,u).
• copyable_edge<VId,true,EV> -> copyable_edge_t<VId,EV> in mandates; retain the copyable_edge/copyable_vertex requires clauses (validate the EProj/VProj result type) and correct the r3 revision note.
• Partition preconditions now throw graph_error (strictly increasing) instead of 'undefined behavior'; remove contradicted duplicate-partition note.
• Fix tab:simple_graph (descriptor model, edge_value type); rewrite adjacency example to descriptor model; fix malformed gvoid snippet header/semicolons.
• Add worked associative/mapped (map<int,vector<pair<int,double>>>) example.
• Resolve \phil notes: operator[] not added; movable EV/VV noted as future work; remove undirected mutable-edge TODO.

Scope split (D3130<->D3131):

• D3130 keeps the normative recognition patterns + see-also pointer; the concrete std-container catalog, trade-off table, and combined examples move to D3131.
• Update both revision histories.

Add agents/d3131_review.md; update agents/D3130_review.md.