Expose instability controls and diagnostics (#72)

docs/INSTABILITY_DIAGNOSTICS.md

@@ -0,0 +1,11 @@
+# Instability controls and diagnostics (Milestone 6, issue #72)
+
+The world-specific NeoForge server config (`serverconfig/rivencraft-server.toml`) is the global policy. `instability.enabled` stops all scheduled effects without changing a saved Age. `instability_providers.<id>` switches each Legacy card independently; these switches do not reroll frozen provider levels. The existing `instability_status_effects`, `instability_decay`, `instability_hazards`, `instability_meteor`, `instability_scorching`, and `instability_erosion` groups provide category policy and action limits. `instability.world_mutation`, hazard/meteor `block_damage`, `player_damage`, and `fire` settings control destructive behavior. `mobGriefing` and `doFireTick` still apply. Defaults retain the Legacy-active hazards; the scheduler, spawn protection, loaded-chunk checks, and per-effect caps remain Rivencraft safety adaptations. The dormant-in-Legacy erosion effect remains enabled for project testing but can be switched off.
+
+Configuration values are read during server operation, but editing the TOML on disk does not guarantee NeoForge will reload it. Restart the server or world after changing the file; `/reload` reloads data packs, not this server config. Per-Age commands below take effect on the next scheduler pass without a restart. A stopped provider does not refund or change the Age's score or saved plan. Existing owned status-effect leases are revoked on their next 20-tick check after global, category, provider, or Age disablement. In-flight meteors are cancelled when their Age or meteor provider is disabled. Existing block changes are not rolled back.
+
+Operators can inspect `/rivencraft age instability [dimension]`. The argument accepts an Age name (quote names containing spaces), a short path such as `fort`, or a full ID such as `rivencraft:age/fort`. Duplicate names require the full ID shown by `/rivencraft age list`. The command reports the frozen score and each saved contribution, the frozen provider IDs/levels and their *current* runtime eligibility, config limits, and whether this Age is enabled. "Eligible" does not promise an effect on the next tick: chance, cooldowns, loaded chunks, player presence, and protection still apply. An unavailable handler is reported as such instead of being mistaken for an active provider. Pre-scoring Ages remain neutral, and missing provider plans from older scored saves are migrated once as described in [runtime policy](INSTABILITY_RUNTIME.md). `/rivencraft age instability disable <dimension>` and `enable <dimension>` are operator-only and persist for that Age alone. Unknown dimensions are rejected. Neither command mutates a book, score, or provider plan.
+
+Newly bound Descriptive Books carry only a server-written numerical potential-instability summary for their tooltip and cover. The details and live enablement stay server-side in the operator command. Older written books receive the summary when opened through the server-approved book screen; until then, an absent tooltip score means "not yet synchronized," not zero. The score does not indicate whether effects are currently enabled.
+
+Manual check: create two scored Ages, disable one with the command, and inspect both. Only the selected Age should show "Age disabled"; its saved breakdown and plan should remain identical. Re-enable it, then switch an individual provider in the world config and restart. Its plan should remain identical while diagnostics show "provider config off." An old neutral Age should report score zero and no selected providers. A non-operator should be unable to invoke the mutation commands. Test tooltips both on a newly bound book and an older book after opening it once.

docs/INSTABILITY_RUNTIME.md

@@ -8,6 +8,8 @@ The server scheduler runs only for loaded `rivencraft:age/*` levels with a playe
 
 Issue #67 registers the non-world-mutating potion handlers; see [status-effect policy](INSTABILITY_STATUS_EFFECTS.md). Issue #68 adds configurable [colored decay](INSTABILITY_DECAY.md), enabled by default for newly generated configs. Issue #69 adds lightning and explosions; issue #70 adds [meteor, scorching, and erosion](INSTABILITY_ENVIRONMENTAL.md). The runtime rejects Overworld and preview dimension IDs; its player requirement excludes unattended snapshot chunk loaders. GameTests cover deterministic selection, save round-trips, score-only migration, unknown IDs, scope checks, fair admission, and action caps.
 
+Issue #72 adds [server config, per-Age controls, diagnostics, and book feedback](INSTABILITY_DIAGNOSTICS.md). Its operator controls never rewrite a frozen score or provider plan.
+
 # Lightning and explosions (#69)
 
 The `lightning` and `explosions` cards now run only in loaded Rivencraft Ages with players. Legacy rolled once per chunk per tick: explosions at 1/1000 and lightning at 1/5000 during thunder or 1/100000 otherwise. Each selected hazard card gets an independent roll every scheduler pass, rather than waiting for the rotating two-provider sample. The roll uses up to 81 already-loaded chunks near Age players and the exact probability of at least one Legacy opportunity over that many chunk-ticks. It permits at most one event per hazard type per pass. A per-Age saved sequence and last-event time prevent the same roll/event from replaying after a restart. Lightning also skips an existing bolt at the target.