docs: factual audit + reference sync — 260 findings corrected

Parallel 6-agent audit against official Anthropic docs (llms-full.txt).
Key corrections applied across permissions, hooks, MCP, security, privacy, reference.yaml.

Highlights:
- Fix MCP config path (~/.claude.json), mcpServers key, variable substitution syntax
- Fix permission modes (5 not 3), :* syntax (×6), Stop event description
- Fix hook JSON field names (hook_event_name, tool_name, tool_input, session_id)
- Fix filesystem restriction docs (permission rules, not settings.json keys)
- Fix data-privacy: 4-tier retention, /bug 5yr warning, ZDR conditions, 5 telemetry opt-out vars
- Add official llms.txt/llms-full.txt references to CLAUDE.md + machine-readable/llms.txt
- Reference.yaml: 375 entries re-synced (92% had wrong line numbers — guide grew 15K→21K lines)
- New script: scripts/resync-reference-yaml.py for automated line number sync
- Quiz: corrected answers for hooks (07), memory settings (03), MCP servers (08)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

machine-readable/llms.txt

@@ -126,6 +126,8 @@ claude-code-ultimate-guide/
 ## Related Resources
 
 - Official: https://docs.anthropic.com/en/docs/claude-code
+- Official llms.txt (index): https://code.claude.com/docs/llms.txt
+- Official llms-full.txt (complete): https://code.claude.com/docs/llms-full.txt
 - DeepWiki: https://deepwiki.com/FlorianBruniaux/claude-code-ultimate-guide
 - Inspiration: https://claudelog.com/
 - Whitepapers (FR + EN): https://www.florian.bruniaux.com/guides — 9 focused whitepapers on Claude Code (foundations, prompting, customization, security, architecture, team, privacy, reference, agent teams)