fix: guard against reserved output name collisions

Address review feedback:
- Skip setting individual outputs for reserved names (cache-hit, versions)
- Emit warning when a tool name conflicts with reserved outputs
- Document dynamic outputs pattern in action.yml comments

action.yml

@@ -90,6 +90,9 @@ outputs:
     description: A boolean value to indicate if a cache was hit.
   versions:
     description: JSON object containing all active tool versions with metadata (version, requested_version, install_path, source).
+  # Dynamic outputs: each active tool (e.g. `node`, `bun`, `python`) is also
+  # set as an individual output whose value is the resolved version string.
+  # Access via ${{ steps.<step-id>.outputs.<tool-name> }}
 runs:
   using: node24
   main: dist/index.js

dist/index.js

@@ -84932,11 +84932,19 @@ async function outputToolVersions() {
         });
         const tools = JSON.parse(output.stdout);
         const activeVersions = {};
+        // Reserved output names that should not be overwritten by tool names
+        const reservedOutputs = ['cache-hit', 'versions'];
         for (const [toolName, versions] of Object.entries(tools)) {
             const activeVersion = versions.find(v => v.active);
             if (activeVersion) {
                 // Set individual output: steps.mise.outputs.bun = "1.0.0"
-                setOutput(toolName, activeVersion.version);
+                // Skip reserved output names to avoid conflicts
+                if (reservedOutputs.includes(toolName)) {
+                    warning(`Tool "${toolName}" conflicts with reserved output name; skipping individual output for this tool.`);
+                }
+                else {
+                    setOutput(toolName, activeVersion.version);
+                }
                 info(`${toolName}: ${activeVersion.version}`);
                 // Collect for JSON output with full metadata
                 activeVersions[toolName] = {

src/index.ts

@@ -169,11 +169,21 @@ async function outputToolVersions(): Promise<void> {
     const tools: Record<string, ToolInfo[]> = JSON.parse(output.stdout)
     const activeVersions: Record<string, ToolVersionOutput> = {}
 
+    // Reserved output names that should not be overwritten by tool names
+    const reservedOutputs = ['cache-hit', 'versions']
+
     for (const [toolName, versions] of Object.entries(tools)) {
       const activeVersion = versions.find(v => v.active)
       if (activeVersion) {
         // Set individual output: steps.mise.outputs.bun = "1.0.0"
-        core.setOutput(toolName, activeVersion.version)
+        // Skip reserved output names to avoid conflicts
+        if (reservedOutputs.includes(toolName)) {
+          core.warning(
+            `Tool "${toolName}" conflicts with reserved output name; skipping individual output for this tool.`
+          )
+        } else {
+          core.setOutput(toolName, activeVersion.version)
+        }
         core.info(`${toolName}: ${activeVersion.version}`)
 
         // Collect for JSON output with full metadata