feat(signals): decode recordings with bounded sigrok output (#2339)

Decode caller-selected protocols from existing recordings through shared
CLI/MCP Evidence. Page literal output lines after complete decoding;
preserve explicit full output, source identity and failed cleanup ownership.

Verified real sigrok-cli 0.7.2 workflows, published UART/SPI/I2C recordings,
independent UART values, selector limits, SDK schemas and cleanup regressions.

Co-authored-by: Olorinm <59321404+Olorinm@users.noreply.github.com>
Assisted-by: Kogasa (gensokyo-skills:kogasa-surprise-testing)

src/application/CapabilityInventory.ts

@@ -44,6 +44,7 @@ type ToolAvailabilityReason = "available" | ToolUnavailabilityReason;
 type ProviderDescriptor = ProviderCapability;
 export type AvailabilityPolicy = {
   readonly packetCaptureEnabled?: boolean;
+  readonly signalRecordingEnabled?: boolean;
   readonly wasmArtifactEnabled?: boolean;
   readonly evmInterfaceEnabled?: boolean;
   readonly processCaptureEnabled: boolean;
@@ -404,6 +405,14 @@ const workflowAvailabilityFor = ({
           remediation:
             "On Linux, supply TShark 4.x via absolute REA_TSHARK_COMMAND and util-linux prlimit (REA_TSHARK_PRLIMIT_COMMAND, default /usr/bin/prlimit). No active binary target or hardware is required; the tool is checked at execution.",
         };
+  if (name === "decode_signal_recording")
+    return policy.signalRecordingEnabled === true
+      ? { reason: "available", remediation: null }
+      : {
+          reason: "provider_missing",
+          remediation:
+            "On Linux, supply sigrok-cli 0.7.2 via absolute REA_SIGROK_COMMAND and util-linux prlimit (REA_SIGROK_PRLIMIT_COMMAND, default /usr/bin/prlimit). No active binary target or hardware is required; the tool is checked at execution.",
+        };
   if (name === "inspect_wasm_artifact")
     return policy.wasmArtifactEnabled === true
       ? { reason: "available", remediation: null }