The message engine outlives its substrate — harvested to Kanban/Changes/ as the change narrator

Step 2 of strategy/01-git-excision.md: CommitMessageEngine and the composer seam relocate to a neutral module renamed away from commit vocabulary (ChangeNarrator, ChangeNarrationRequest, ChangeNarrating, SemanticChangeNarration, ChangeAuthorship), GitChangedPath extracts from GitCommitOperation as ChangedPath, and the one git tie severs — authorship's foreign case carries a display name, not a GitIdentity. The spec tests transplant as ChangeNarratorTests, alive until the journal work begins. 3,009 tests green.

Claude-Session: https://claude.ai/code/session_014PtZdPwqZuqEDLc6wZMtEy

KanbanTests/AutoCommitTests.swift

@@ -619,14 +619,14 @@ struct AutoCommitStageAroundTests {
 /// A composer that takes its time, so a test can hold a flush open and drive the close sequence into
 /// the gap. Everything else about it is the real one — this suite asserts *when* a commit exists, and
 /// a fake message would make the commits it reads back unrecognisable.
-private struct SlowComposer: CommitMessageComposing {
+private struct SlowComposer: ChangeNarrating {
     let delay: TimeInterval
 
-    func message(for request: CommitMessageRequest) -> String {
+    func narrative(for request: ChangeNarrationRequest) -> String {
         // Blocking, deliberately: this runs on the flush's own detached task, and what the test needs
         // held open is that task rather than the actor the close sequence is running on.
         Thread.sleep(forTimeInterval: delay)
-        return CommitMessageEngine.message(for: request)
+        return ChangeNarrator.narrative(for: request)
     }
 }
 
@@ -1336,7 +1336,7 @@ struct AutoCommitMessageTests {
     /// its subject describes a board that has not heard about the card it is committing.
     @Test("Without the await the subject is the one the stale snapshot could compose — the defect, pinned")
     func aStaleSnapshotComposesTheShrug() async throws {
-        #expect(try await flushRacingItsReload(awaitsCoverage: false) == CommitMessageEngine.unnamedSubject)
+        #expect(try await flushRacingItsReload(awaitsCoverage: false) == ChangeNarrator.unnamedSubject)
     }
 
     /// The bound is a bound: a board whose watcher stream never came up has no reload to wait for, and
@@ -1345,7 +1345,7 @@ struct AutoCommitMessageTests {
     func theWaitIsBounded() async throws {
         // The generation never moves, so the wait runs to its (millisecond) deadline and composes.
         #expect(try await flushRacingItsReload(awaitsCoverage: true, landsAfterReads: .max)
-            == CommitMessageEngine.unnamedSubject)
+            == ChangeNarrator.unnamedSubject)
     }
 }
 
@@ -1380,8 +1380,8 @@ struct CommitAttributionRuleTests {
         try fixture.item("lane/card", stamped("Moved", by: "claude"))
 
         let paths = [
-            GitChangedPath(path: "old/card/index.md", isDeletion: true, isRename: true),
-            GitChangedPath(path: "lane/card/index.md", isDeletion: false, isRename: true)
+            ChangedPath(path: "old/card/index.md", isDeletion: true, isRename: true),
+            ChangedPath(path: "lane/card/index.md", isDeletion: false, isRename: true)
         ]
         // "**A folder move is not a deletion**: items match by id across the whole board."
         #expect(CommitAttribution.foreignIdentity(for: paths, under: fixture.root).name == "claude")
@@ -1391,7 +1391,7 @@ struct CommitAttributionRuleTests {
     func departuresAloneFallBack() throws {
         let fixture = try WriterFixture()
         defer { fixture.tearDown() }
-        let paths = [GitChangedPath(path: "old/card/index.md", isDeletion: true, isRename: true)]
+        let paths = [ChangedPath(path: "old/card/index.md", isDeletion: true, isRename: true)]
         #expect(CommitAttribution.foreignIdentity(for: paths, under: fixture.root)
             == CommitAttribution.externalIdentity)
     }
@@ -1417,7 +1417,7 @@ struct CommitAttributionRuleTests {
         let file = EchoLedger.key(fixture.url("lane/card").appendingPathComponent("index.md"))
         let matching = [file: HarvestedReceipt(receipt: .content(hash: EchoLedger.hash(of: text)), isHeal: false)]
         let stale = [file: HarvestedReceipt(receipt: .content(hash: EchoLedger.hash(of: "other")), isHeal: false)]
-        let changed = [GitChangedPath(path: "lane/card/index.md", isDeletion: false, isRename: false)]
+        let changed = [ChangedPath(path: "lane/card/index.md", isDeletion: false, isRename: false)]
 
         #expect(CommitAttribution.split(changed, under: fixture.root, receipts: matching).user == changed)
         // "a foreign edit landing on an app-written path inside the same window misses the hash and
@@ -1436,7 +1436,7 @@ struct CommitAttributionRuleTests {
 
         let file = EchoLedger.key(fixture.url("lane/card").appendingPathComponent("index.md"))
         let receipts = [file: HarvestedReceipt(receipt: .content(hash: EchoLedger.hash(of: text)), isHeal: true)]
-        let changed = [GitChangedPath(path: "lane/card/index.md", isDeletion: false, isRename: false)]
+        let changed = [ChangedPath(path: "lane/card/index.md", isDeletion: false, isRename: false)]
 
         let split = CommitAttribution.split(changed, under: fixture.root, receipts: receipts)
         #expect(split.heal == changed)