Replace 'App:' prompt prefix with natural-language phrasing

Cotabby/Support/FoundationModelPromptRenderer.swift

@@ -107,7 +107,7 @@ enum FoundationModelPromptRenderer {
 
         var sections = [
             "Screen context:",
-            "App: \(request.context.applicationName)"
+            "User is on \(request.context.applicationName)."
         ]
 
         if let summary = request.visualContextSummary,

Cotabby/Support/LlamaPromptRenderer.swift

@@ -57,7 +57,7 @@ enum LlamaPromptRenderer {
 
         sections.append("")
         sections.append("Screen context:")
-        sections.append("App: \(applicationName)")
+        sections.append("User is on \(applicationName).")
         if let summary = visualContextSummary, !summary.isEmpty {
             sections.append("Screen content:")
             sections.append(summary)

CotabbyTests/LlamaPromptRendererTests.swift

@@ -91,7 +91,7 @@ final class LlamaPromptRendererTests: XCTestCase {
             userName: nil
         )
 
-        XCTAssertTrue(prompt.contains("App: Slack"))
+        XCTAssertTrue(prompt.contains("User is on Slack."))
         XCTAssertTrue(prompt.contains("My prefix text here"))
     }
 

CotabbyTests/PromptPolicyTests.swift

@@ -48,7 +48,7 @@ final class FoundationModelPromptRendererTests: XCTestCase {
 
         let prompt = FoundationModelPromptRenderer.prompt(for: request)
 
-        XCTAssertTrue(prompt.contains("App: TestApp"))
+        XCTAssertTrue(prompt.contains("User is on TestApp."))
         XCTAssertTrue(prompt.contains("  Hello from the field  "))
     }