KB Config SSOT Fix

What: Core/obsidian-config/ was a dead leftover from the pre-unification multi-vault design (originally _shared/obsidian-config/, synced to each vault’s .obsidian/ via sync-vaults.sh). That script no longer exists; the dir hadn’t been touched since 2026-05-27 while the real live config — root .obsidian/ — updates continuously. Two configs, one dead: SSOT violation.

Fix:

• Moved Core/obsidian-config/ aside, then hard-deleted on Talbot’s explicit confirm (content is in git history + my_backup)
• Fixed stale reference in .graphifyignore (line 11)
• MBR/.obsidian/ left alone — separate live nested-vault config, unrelated to this violation

Task: archived to Tasks/archive/2026-07/