feat(codeowners): org default + per-repo recommendations

[hkimw]

Summary

• Add an org default CODEOWNERS file routing all files plus docs, RTL, and editor paths to @hkimw.
• Add per-repo CODEOWNERS recommendations for future contributor groups.
• Cite kv260 path conventions for documentation, RTL, verification, FPGA flow, driver, config, scripts, tools, and evidence ownership.

Evidence State

Evidence state: markdown whitespace check clean; public wording scan clean; commit and push hooks completed.

Review

• Scope is bounded to .github/CODEOWNERS and docs/codeowners-recommendations.md.
• No repo settings, release, tag, or visibility changes.