Remove stale AI-generated documentation

Drop seven planning/strategy/upgrade-notes docs that have outlived their
usefulness, plus the dangling CODEX-TOR-GUIDE.md reference in
tor_embedded.cpp.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/tor/tor_embedded.cpp

@@ -3,7 +3,6 @@
 // Distributed under the MIT/X11 software license
 //
 // BUILD REQUIREMENT: Link against libtor.a built from the official Tor source.
-// See CODEX-TOR-GUIDE.md for submodule setup and build instructions.
 //
 // This file compiles in two modes:
 //   1. ENABLE_TOR_EMBEDDED defined: full embedded Tor via tor_api.h