Docs: move benchmark tables to strided-rs-benchmark-suite; fix stale versions and faer_design.md claims

[shinaoka]

Part of #199 (Phase 3, docs). All file:line references are pinned to origin/main at 9da9b9f. Violations of the repository's own benchmark rule (results live in strided-rs-benchmark-suite; crate READMEs document usage and contracts).

• strided-kernel/README.md:186 onward: 161 lines / 67 table rows of performance results move to the suite repo; keep a link. (The retiring crates' README tables leave with Phase 2.)
• Stale version strings "0.1" in root README.md:49, strided-rs/README.md:11, :54, :61, strided-perm/README.md:33 (workspace is 0.3.0).
• docs/faer_design.md stale claims: the per-element ok_or reduce path it criticizes no longer exists; inner_loop_map1 moved from kernel.rs to map_view.rs:153; the contiguous-identity memcpy fast path and the pulp SIMD reduce it lists as future work are implemented (ops_view.rs:209, simd.rs); it carries a perf table inside a design doc.
• strided-kernel/README.md Scope section omits the entire prepared-plan surface (about 25 public types: CopyPlan, typed plans, all Erased*Plan, fused_elementwise_into, batched_outer_product_into); document them.
• Move the five docs/*-worklog.md files into docs/worklogs/ and the design docs into docs/design/, and add the "docs/plans/ is historical, do not update" note to AGENTS.md (convention from tenferro).