Continue patching UOM APIs.

Author: ShikiSuen

Sources/Megrez/3_KeyValuePaired.swift

@@ -403,7 +403,9 @@ extension Megrez {
 
     // 選擇用來形成觀測 key 的資料源：長→短使用 after，其他使用 before
     let keySource = isBreakingUp ? currentAssembled : previouslyAssembled
-    let keyCursor = afterHit.range.upperBound // 與現有 key 生成方法對齊
+    let keyCursorRaw = Swift.max(afterHit.range.lowerBound, afterHit.range.upperBound - 1)
+    guard keySource.totalKeyCount > 0 else { return nil }
+    let keyCursor = Swift.max(0, Swift.min(keyCursorRaw, keySource.totalKeyCount - 1))
 
     guard let keyGen = keySource.generateKeyForPerception(cursor: keyCursor) else { return nil }
 

Tests/MegrezTests/MegrezTests.swift

@@ -671,9 +671,11 @@ final class MegrezTestsAdvanced: XCTestCase {
     ) {
       obsCaptured = $0
     }
+    XCTAssertEqual(obsCaptured?.ngramKey, "((zai4:再),(chuang4:創),shi4)")
     // compositor.assemble() <- 已經組句了。
     let assembledAfter = compositor.assembledSentence.map(\.value).joined(separator: " ")
     XCTAssertTrue("再 創 世 的 凱歌" == assembledAfter)
+    // ====
     let cursorShiDe = 3
     let prevAssembly = compositor.assembledSentence
     obsCaptured = nil
@@ -683,8 +685,9 @@ final class MegrezTestsAdvanced: XCTestCase {
     ) {
       obsCaptured = $0
     }
+    XCTAssertEqual(obsCaptured?.ngramKey, "((chuang4:創),(shi4:世),de5)")
     XCTAssertTrue(overrideSucceeded)
-    let currentAssembly = compositor.assemble()
+    let currentAssembly = compositor.assembledSentence
     guard let afterHit = currentAssembly.findGram(at: cursorShiDe) else {
       XCTFail("Expected current gram at cursor \(cursorShiDe)")
       return