test(contracts): CFI/context winner must land intact through conflict resolution

Book-side twin of the audio-survival test, closing H1's verification
list. Scenario: web push carries percentage + epubcfi + context_text;
a koreader-style percentage-only push from a second source within the
window detects a conflict; the user resolves with the CFI-carrying
side. The funneled resolution must land the winner's ENTIRE locator
pair — percentage 0.5, epubcfi, context_text together (the old direct
writer NULLed context_text and character_offset, breaking the coherent
pair the far-anchor work established) — and must not spawn a duplicate
pending conflict.

cmd/server/tests/contract_pins_test.go

@@ -894,6 +894,90 @@ func TestH1_SyncQueueFlush_LandsAndPreservesAudio(t *testing.T) {
 		"the flush must preserve audio_offset_seconds (LWW seed), not NULL it")
 }
 
+// TestH1_ConflictResolutionPreservesCFIPair is the BOOK-side twin of the
+// audio test: a winner carrying epubcfi + context_text must land with its
+// locator pair intact — the far-anchor doctrine's coherent pair — instead
+// of the old direct-write behavior that NULLed context_text and
+// character_offset (because they weren't in its param list), leaving a
+// winner CFI standing next to nothing.
+func TestH1_ConflictResolutionPreservesCFIPair(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping integration test in short mode")
+	}
+	setup := setupTestServer(t)
+	fx := createContractFixture(t, setup)
+	progress := progressURL(setup.Server.URL, fx.itemID)
+
+	// Push 1 (web): percentage + the full CFI/context anchor pair.
+	cfi := "epubcfi(/6/4/2:15)"
+	context := "the contract pin context sentence"
+	resp := doReq(t, "PUT", progress, map[string]interface{}{
+		"percentage":   0.5,
+		"epubcfi":      cfi,
+		"context_text": context,
+	}, setup.Token)
+	defer resp.Body.Close()
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+
+	// Push 2 within the window from a second source: percentage-only (the
+	// koreader-style push) -> conflict detected against push 1.
+	deviceToken := createContractDeviceNamed(t, setup, "koreader", "koreader")
+	push2Req, err := http.NewRequest("PUT", progress,
+		strings.NewReader(`{"percentage": 0.3}`))
+	require.NoError(t, err)
+	push2Req.Header.Set("Content-Type", "application/json")
+	push2Req.Header.Set("Authorization", "Bearer "+setup.Token)
+	push2Req.Header.Set("X-Device-Token", deviceToken)
+	resp2, err := (&http.Client{}).Do(push2Req)
+	require.NoError(t, err)
+	require.Equal(t, http.StatusOK, resp2.StatusCode)
+	resp2.Body.Close()
+
+	// Find the detected conflict.
+	listResp := doReq(t, "GET", setup.Server.URL+"/api/conflicts", nil, setup.Token)
+	defer listResp.Body.Close()
+	require.Equal(t, http.StatusOK, listResp.StatusCode)
+	list := decodeJSON(t, listResp)
+	var conflictID string
+	for _, raw := range list["conflicts"].([]interface{}) {
+		col := raw.(map[string]interface{})
+		if col["media_item_id"] == fx.itemID && col["conflict_type"] == "progress" && col["resolution_status"] == "unresolved" {
+			conflictID, _ = col["id"].(string)
+		}
+	}
+	require.NotEmpty(t, conflictID, "two-source push should detect a progress conflict")
+
+	// Resolve with the CFI-carrying side as winner.
+	resolve := doReq(t, "POST", setup.Server.URL+"/api/conflicts/"+conflictID+"/resolve", map[string]interface{}{
+		"winner": "web",
+	}, setup.Token)
+	defer resolve.Body.Close()
+	require.Equal(t, http.StatusOK, resolve.StatusCode)
+
+	// The winner's ENTIRE locator pair lands: percentage, epubcfi AND
+	// context_text together (the old write NULLed the context), and the
+	// loser's percentage does not.
+	get := doReq(t, "GET", progress, nil, setup.Token)
+	defer get.Body.Close()
+	require.Equal(t, http.StatusOK, get.StatusCode)
+	row := decodeJSON(t, get)
+	require.Equal(t, 0.5, getFloatField(t, row, "percentage"))
+	require.Equal(t, cfi, getStringField(t, row, "epubcfi"))
+	require.Equal(t, context, getStringField(t, row, "context_text"))
+
+	// No duplicate pending conflict from the funneled resolution write.
+	get2 := doReq(t, "GET", setup.Server.URL+"/api/conflicts", nil, setup.Token)
+	defer get2.Body.Close()
+	require.Equal(t, http.StatusOK, get2.StatusCode)
+	for _, raw := range decodeJSON(t, get2)["conflicts"].([]interface{}) {
+		col := raw.(map[string]interface{})
+		if col["media_item_id"] == fx.itemID && col["conflict_type"] == "progress" {
+			require.Equal(t, "user_resolved", col["resolution_status"],
+				"resolution must not spawn a duplicate pending conflict")
+		}
+	}
+}
+
 // ---------------------------------------------------------------------------
 // 7. H1 verification — resolving a conflict must preserve unknown fields
 // ---------------------------------------------------------------------------