fix(activate): wire .catch on void-prefixed postMessageToWebview sites

The five bare `void` prefixes in registerCommands.ts satisfy
no-floating-promises but rely on ClineProvider.postMessageToWebview
having its own try/catch — an implicit contract that a future
change could break without notice. Matching #253's pattern, each
void site now also installs a .catch arm that logs to outputChannel.

Added a parameterized test asserting the .catch arm runs and logs
when postMessageToWebview rejects, so a future regression in the
implicit-swallow contract is caught at the test boundary.

Author: 0xMink

src/activate/__tests__/registerCommands.spec.ts

@@ -246,4 +246,28 @@ describe("registerCommands handlers", () => {
 
 		expect(mockProvider.postMessageToWebview).not.toHaveBeenCalled()
 	})
+
+	// Representative coverage for the .catch arm on all five void-prefixed
+	// postMessageToWebview sites in registerCommands.ts (settingsButtonClicked
+	// posts twice, plus historyButtonClicked, marketplaceButtonClicked, and
+	// acceptInput). Each handler is synchronous, so the .catch arm runs on a
+	// microtask; awaiting Promise.resolve() flushes it before we assert.
+	it.each([
+		{ command: "zoo-code.settingsButtonClicked", expectedCalls: 2 },
+		{ command: "zoo-code.historyButtonClicked", expectedCalls: 1 },
+		{ command: "zoo-code.marketplaceButtonClicked", expectedCalls: 1 },
+		{ command: "zoo-code.acceptInput", expectedCalls: 1 },
+	])("$command logs to outputChannel when postMessageToWebview rejects", async ({ command, expectedCalls }) => {
+		const boom = new Error("boom")
+		mockVisibleProvider.postMessageToWebview.mockReset()
+		mockVisibleProvider.postMessageToWebview.mockRejectedValue(boom)
+
+		handlers[command]()
+
+		// Flush microtasks so the chained .catch arm runs.
+		await new Promise((resolve) => setImmediate(resolve))
+
+		expect(mockOutputChannel.appendLine).toHaveBeenCalledTimes(expectedCalls)
+		expect(mockOutputChannel.appendLine).toHaveBeenCalledWith(`postMessageToWebview failed: ${boom}`)
+	})
 })

src/activate/registerCommands.ts

@@ -103,9 +103,13 @@ const getCommandsMap = ({ context, outputChannel, provider }: RegisterCommandOpt
 
 		TelemetryService.instance.captureTitleButtonClicked("settings")
 
-		void visibleProvider.postMessageToWebview({ type: "action", action: "settingsButtonClicked" })
+		void visibleProvider
+			.postMessageToWebview({ type: "action", action: "settingsButtonClicked" })
+			.catch((error) => outputChannel.appendLine(`postMessageToWebview failed: ${error}`))
 		// Also explicitly post the visibility message to trigger scroll reliably
-		void visibleProvider.postMessageToWebview({ type: "action", action: "didBecomeVisible" })
+		void visibleProvider
+			.postMessageToWebview({ type: "action", action: "didBecomeVisible" })
+			.catch((error) => outputChannel.appendLine(`postMessageToWebview failed: ${error}`))
 	},
 	historyButtonClicked: () => {
 		const visibleProvider = getVisibleProviderOrLog(outputChannel)
@@ -116,12 +120,16 @@ const getCommandsMap = ({ context, outputChannel, provider }: RegisterCommandOpt
 
 		TelemetryService.instance.captureTitleButtonClicked("history")
 
-		void visibleProvider.postMessageToWebview({ type: "action", action: "historyButtonClicked" })
+		void visibleProvider
+			.postMessageToWebview({ type: "action", action: "historyButtonClicked" })
+			.catch((error) => outputChannel.appendLine(`postMessageToWebview failed: ${error}`))
 	},
 	marketplaceButtonClicked: () => {
 		const visibleProvider = getVisibleProviderOrLog(outputChannel)
 		if (!visibleProvider) return
-		void visibleProvider.postMessageToWebview({ type: "action", action: "marketplaceButtonClicked" })
+		void visibleProvider
+			.postMessageToWebview({ type: "action", action: "marketplaceButtonClicked" })
+			.catch((error) => outputChannel.appendLine(`postMessageToWebview failed: ${error}`))
 	},
 	newTask: handleNewTask,
 	setCustomStoragePath: async () => {
@@ -170,7 +178,9 @@ const getCommandsMap = ({ context, outputChannel, provider }: RegisterCommandOpt
 			return
 		}
 
-		void visibleProvider.postMessageToWebview({ type: "acceptInput" })
+		void visibleProvider
+			.postMessageToWebview({ type: "acceptInput" })
+			.catch((error) => outputChannel.appendLine(`postMessageToWebview failed: ${error}`))
 	},
 	toggleAutoApprove: async () => {
 		const visibleProvider = getVisibleProviderOrLog(outputChannel)