feat: integrate floor pricing with mutable pricing system

Rebased on main to incorporate floor pricing changes (commit 6cb08ce) and
made MINIMUM_STORAGE_RATE_PER_MONTH mutable to enable runtime updates.

Changes:
- Converted minimumStorageRatePerMonth from immutable to storage variable
- Added MAX_MINIMUM_STORAGE_RATE_PER_MONTH (0.24 USDFC, 4x initial 0.06)
- Updated updatePricing() to accept newMinimumRate parameter
- Updated PricingUpdated event to include minimumRate
- Updated getCurrentPricingRates() to return both storage price and minimum rate
- Added AtLeastOnePriceMustBeNonZero and PriceExceedsMaximum errors
- Updated all references throughout contract to use camelCase variable names

Author: rjan90

service_contracts/abi/Errors.abi.json

@@ -10,6 +10,11 @@
       }
     ]
   },
+  {
+    "type": "error",
+    "name": "AtLeastOnePriceMustBeNonZero",
+    "inputs": []
+  },
   {
     "type": "error",
     "name": "CDNPaymentAlreadyTerminated",
@@ -715,6 +720,27 @@
       }
     ]
   },
+  {
+    "type": "error",
+    "name": "PriceExceedsMaximum",
+    "inputs": [
+      {
+        "name": "priceType",
+        "type": "string",
+        "internalType": "string"
+      },
+      {
+        "name": "maxAllowed",
+        "type": "uint256",
+        "internalType": "uint256"
+      },
+      {
+        "name": "actual",
+        "type": "uint256",
+        "internalType": "uint256"
+      }
+    ]
+  },
   {
     "type": "error",
     "name": "ProofAlreadySubmitted",

service_contracts/abi/FilecoinWarmStorageService.abi.json

@@ -292,12 +292,7 @@
         "internalType": "uint256"
       },
       {
-        "name": "cacheMissPrice",
-        "type": "uint256",
-        "internalType": "uint256"
-      },
-      {
-        "name": "cdnPrice",
+        "name": "minimumRate",
         "type": "uint256",
         "internalType": "uint256"
       }
@@ -826,12 +821,7 @@
         "internalType": "uint256"
       },
       {
-        "name": "newCacheMissPrice",
-        "type": "uint256",
-        "internalType": "uint256"
-      },
-      {
-        "name": "newCdnPrice",
+        "name": "newMinimumRate",
         "type": "uint256",
         "internalType": "uint256"
       }
@@ -1343,13 +1333,7 @@
         "internalType": "uint256"
       },
       {
-        "name": "cacheMissPrice",
-        "type": "uint256",
-        "indexed": false,
-        "internalType": "uint256"
-      },
-      {
-        "name": "cdnPrice",
+        "name": "minimumRate",
         "type": "uint256",
         "indexed": false,
         "internalType": "uint256"

service_contracts/src/Errors.sol

@@ -326,4 +326,13 @@ library Errors {
     error InsufficientMaxLockupPeriod(
         address payer, address operator, uint256 maxLockupPeriod, uint256 requiredLockupPeriod
     );
+
+    /// @notice At least one price parameter must be non-zero when updating pricing
+    error AtLeastOnePriceMustBeNonZero();
+
+    /// @notice Price update exceeds the maximum allowed value
+    /// @param priceType The type of price being updated (e.g., "storage", "minimumRate")
+    /// @param maxAllowed The maximum allowed value for this price type
+    /// @param actual The attempted value that exceeds the maximum
+    error PriceExceedsMaximum(string priceType, uint256 maxAllowed, uint256 actual);
 }

service_contracts/src/FilecoinWarmStorageService.sol

@@ -490,10 +490,7 @@ contract FilecoinWarmStorageService is
      * @param newStoragePrice New storage price per TiB per month (0 = no change, max 10 USDFC)
      * @param newMinimumRate New minimum monthly storage rate (0 = no change, max 0.24 USDFC)
      */
-    function updatePricing(uint256 newStoragePrice, uint256 newMinimumRate)
-        external
-        onlyOwner
-    {
+    function updatePricing(uint256 newStoragePrice, uint256 newMinimumRate) external onlyOwner {
         if (newStoragePrice == 0 && newMinimumRate == 0) {
             revert Errors.AtLeastOnePriceMustBeNonZero();
         }
@@ -1402,11 +1399,7 @@ contract FilecoinWarmStorageService is
      * @return storagePrice Current storage price per TiB per month
      * @return minimumRate Current minimum monthly storage rate
      */
-    function getCurrentPricingRates()
-        external
-        view
-        returns (uint256 storagePrice, uint256 minimumRate)
-    {
+    function getCurrentPricingRates() external view returns (uint256 storagePrice, uint256 minimumRate) {
         return (storagePricePerTibPerMonth, minimumStorageRatePerMonth);
     }
 

service_contracts/src/lib/FilecoinWarmStorageServiceLayout.sol

@@ -25,3 +25,5 @@ bytes32 constant APPROVED_PROVIDER_IDS_SLOT = bytes32(uint256(16));
 bytes32 constant VIEW_CONTRACT_ADDRESS_SLOT = bytes32(uint256(17));
 bytes32 constant FIL_BEAM_CONTROLLER_ADDRESS_SLOT = bytes32(uint256(18));
 bytes32 constant NEXT_UPGRADE_SLOT = bytes32(uint256(19));
+bytes32 constant STORAGE_PRICE_PER_TIB_PER_MONTH_SLOT = bytes32(uint256(20));
+bytes32 constant MINIMUM_STORAGE_RATE_PER_MONTH_SLOT = bytes32(uint256(21));