DOCFIX-168: proposed netem parameters + ULA/GUA generation guidance (gaps #4(d)+11); tracker sync ...

docs/dc-dc-netem-and-ula-gua-proposal.md: a concrete, reasoned netem
parameter proposal (1ms/0.2ms jitter/0.01% loss/uncapped rate) for operator
ratification, plus the exact safe command (openssl rand -hex 5, RFC
4193-compliant) for the operator to generate the real org ULA /48
themselves. Deliberately does not generate the GUA carve or DC2's supernet
-- both need real ARIN/NetBox coordination this session has no authority
or visibility to perform.

Also finalizes docs/dc-dc-deployment-workflow.md and docs/session-ledger.md
across all seven gap-closure deliveries tonight (DOCFIX-162 through 168):
tooling gap register items #4(d), #5, #6, #7, #11, #12, #13, #14, #15, #16
updated to their real closed/partial state, new gap #17 added, harness-debt
item #10 corrected. Full test gauntlet re-run clean: same pre-existing
environment-gap failures as every earlier check tonight (jq missing on
this workstation), zero regressions across all seven new script families.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QrcJx8TUar7pYAvpGJw57A