Define knowledge persistence requirements

Docs/KnowledgeAndSkillFoundation.md

@@ -536,3 +536,40 @@ Guardrails:
 
 Anti-exploit rule: rewards should come from meaningful decisions, varied
 practice, and good recovery, not from low-cost repetition.
+
+## Knowledge Persistence Requirements
+
+Knowledge and skill state must survive save/load, server restarts, and future
+character handoff systems without resetting learning progress or tutorial
+fatigue.
+
+Persisted state:
+
+- Stable knowledge profile ID linked to the player character or NPC.
+- Learned concepts by stable concept ID.
+- Practical skill experience by taxonomy domain.
+- Mastery/confidence tier per topic, separate from raw experience.
+- Failed attempts that produced useful feedback, including cause category,
+  recovery action, and recent cooldown state.
+- Tutorial and contextual prompt state: seen, dismissed, repeated, snoozed, and
+  next eligible display time.
+- Optional knowledge checks answered, skipped, failed, or recently displayed.
+- Teaching, observation, and shared-work learning events that granted credit.
+- Schema version, migration marker, and source build/version for future cleanup.
+
+Save/load rules:
+
+- The server is authoritative for writes in multiplayer.
+- Client UI may cache prompt visibility, but save data comes from validated
+  server state.
+- Save enough recent action and prompt history to prevent reset-based farming.
+- Keep learned concepts stable across wording changes in the question bank.
+- Preserve failed attempts long enough to support better feedback and avoid
+  repeating the same hint every few seconds.
+- Store tutorial state per character/profile, not globally across all worlds.
+- Never store private credentials, personal account data, or real-world source
+  notes in player save records.
+
+Persistence rule: learning state should make a returning character feel
+continuous while giving designers enough history to tune teaching, feedback, and
+anti-exploit behavior.