Release hygiene: sync CHANGELOG and version metadata for 1.0.1

[jose-compu]

Summary

Post-1.0.0 release hygiene: CHANGELOG still marks several shipped 0.x releases as (unreleased), LOGOSDB_VERSION_* in the public header lags at 0.9.0, MCP self-reports 0.11.0, and docs (README roadmap, SECURITY.md supported versions, RELEASING.md examples) still read as pre-1.0.

Scope

• Date and close out CHANGELOG entries for shipped 0.9.1–0.12.0 and add a proper 1.0.0 section
• Add 1.0.1 patch entry for this hygiene release
• Align version metadata: logosdb.h, CMakeLists.txt, pyproject.toml, nodejs/mcp/n8n package.json, MCP server self-reported version, workspace lockfile / logosdb dependency ranges
• Update .md docs for post-1.0 semver / supported versions / release examples

Acceptance

• All package and library version strings report 1.0.1
• CHANGELOG has no stale (unreleased) markers for versions already shipped
• README / SECURITY / RELEASING reflect stable 1.x support

Out of scope

• Feature work, Windows port (Windows support: abstract POSIX file I/O behind a portable layer #10), remaining Python adapter audit (Security: audit python/logosdb/* integration adapters (passthrough, paths, secrets) #111)