feat(builder): add a Production tab telling you how to instrument a build

Everything needed to instrument a production build was in the source, so
using it meant reading the source. The dialog now says how, with the
commands already filled in for this machine: the path comes from
SystemConfigOverride rather than being written out a second time, so the
two cannot drift, and the date is today's, which is the one that will
work. It switches to Windows syntax on Windows.

It explains why each step is there as well as what to type - why a root
owned folder is what proves an admin allowed it, why the permission
expires by itself, and why the app has to start twice before it takes.
Knowing that is what stops the second restart looking like a bug.

Author: abose

src/phoenix-builder/builder-connect-dialog.html

@@ -4,6 +4,7 @@ <h1 class="dialog-title">Phoenix Builder MCP</h1>
         <ul class="nav nav-tabs no-focus" style="margin-bottom: 0;">
             <li class="active"><a href="#builder-settings" data-toggle="tab">Settings</a></li>
             <li><a href="#builder-logs" data-toggle="tab">Console Logs</a></li>
+            <li><a href="#builder-prod" data-toggle="tab">Production</a></li>
         </ul>
     </div>
     <div class="modal-body tab-content">
@@ -61,6 +62,36 @@ <h1 class="dialog-title">Phoenix Builder MCP</h1>
                 <span style="opacity: 0.5;">No logs captured yet.</span>
             </div>
         </div>
+        <div id="builder-prod" class="tab-pane">
+            <p class="dialog-message">
+                MCP is off in production builds. To instrument one, a machine admin drops a dated
+                permission in a root owned folder &mdash; being able to write there is what proves an
+                admin allowed it. It is a date, not a switch, so a permission cannot be left on by
+                accident: it works on that day only.
+            </p>
+
+            <p style="font-weight: bold; margin-bottom: 4px;">1. Grant it (click to copy, then run in a terminal)</p>
+            <pre class="builder-config-code" style="padding: 8px; border: 1px solid var(--item-border-color); border-radius: 4px; overflow-x: auto; font-size: 12px; cursor: pointer; white-space: pre-wrap; word-break: break-all;" title="Click to copy">{{mcpGrantCommand}}</pre>
+            <p style="font-size: 12px; opacity: 0.7; margin-top: 4px;">
+                Writes <code>{{mcpOverrideFile}}</code> with today's date, <code>{{mcpToday}}</code>.
+                Re-run it on any day you want to instrument again.
+            </p>
+
+            <p style="font-weight: bold; margin-bottom: 4px; margin-top: 12px;">2. Restart the production app twice</p>
+            <p style="font-size: 12px; opacity: 0.7; margin-top: 0;">
+                Nothing else to switch on &mdash; the file is the permission, and the app picks it up
+                by itself. Boot reads no files, to keep startup quick, so it consults a cached copy of
+                the date: the first start after step 1 caches it, the second acts on it. Removing the
+                file clears the cache the same way, one start later.
+            </p>
+
+            <p style="font-weight: bold; margin-bottom: 4px; margin-top: 12px;">Revoking</p>
+            <pre class="builder-config-code" style="padding: 8px; border: 1px solid var(--item-border-color); border-radius: 4px; overflow-x: auto; font-size: 12px; cursor: pointer; white-space: pre-wrap; word-break: break-all;" title="Click to copy">{{mcpRevokeCommand}}</pre>
+            <p style="font-size: 12px; opacity: 0.7; margin-top: 4px;">
+                It also lapses on its own at midnight. While anything is connected the production
+                window shows a red <b>Remote Controlled</b> badge in its status bar.
+            </p>
+        </div>
     </div>
     <div class="modal-footer">
         <button class="dialog-button btn primary" data-button-id="ok">Done</button>

src/phoenix-builder/main.js

@@ -179,11 +179,34 @@ define(function (require, exports, module) {
         let url = localStorage.getItem("phoenixBuilderWsUrl") || DEFAULT_WS_URL,
             enabled = localStorage.getItem("phoenixBuilderEnabled") === "true";
 
+        // Ready to run, so the Production tab needs nothing looked up elsewhere.
+        // The path comes from SystemConfigOverride rather than being written out
+        // again here, so the two cannot drift apart.
+        const overrideFile = Phoenix.fs.getTauriPlatformPath(SystemConfigOverride.OVERRIDE_FILE_PATH);
+        const overrideDir = overrideFile.replace(/[/\\][^/\\]+$/, "");
+        const now = new Date();
+        const today = now.getFullYear() + "-" +
+            String(now.getMonth() + 1).padStart(2, "0") + "-" +
+            String(now.getDate()).padStart(2, "0");
+        const isWin = Phoenix.platform === "win";
+        const grantCommand = isWin
+            ? 'mkdir "' + overrideDir + '" & echo {"' + PROD_OVERRIDE_DATE_KEY + '": "' + today +
+                '"} > "' + overrideFile + '"'
+            : 'sudo mkdir -p "' + overrideDir + '" && echo \'{"' + PROD_OVERRIDE_DATE_KEY +
+                '": "' + today + '"}\' | sudo tee "' + overrideFile + '"';
+        const revokeCommand = isWin
+            ? 'del "' + overrideFile + '"'
+            : 'sudo rm "' + overrideFile + '"';
+
         const templateVars = {
             url: url,
             enabled: enabled,
             connected: PhoenixBuilderClient.isConnected(),
-            instanceName: PhoenixBuilderClient.getInstanceName()
+            instanceName: PhoenixBuilderClient.getInstanceName(),
+            mcpOverrideFile: overrideFile,
+            mcpToday: today,
+            mcpGrantCommand: grantCommand,
+            mcpRevokeCommand: revokeCommand
         };
 
         const template = Mustache.render(BuilderConnectTemplate, templateVars);