Prepare scoped lifecycle projection and align authoring guide

crates/oa-desktop/src/guide.rs

@@ -491,18 +491,18 @@ fn article(topic: Topic) -> Article {
                             &[
                                 "Open Behavior & scenarios, choose Scenario under Create element and add it at a legal root/owner. Select the scenario in the behavior selector.",
                                 "Use + Lifeline and choose the participant or work it represents. Choices follow the scenario's viewpoint: operational activities, operational participants, system functions or system boundary participants.",
-                                "Choose + Message and its style. Call + correlated reply creates both occurrences in one edit. Select the exchange and compatible sending/receiving lifelines. Reply to existing call offers valid unanswered calls.",
-                                "Use Action, Observe state or Fragment for other behavior. A local timer has an expression and a lifeline, with no global exchange. Create and delete messages describe participant lifetime; Model checks also flag risks inside repeated loops.",
-                                "Choose a message style and Draw message. Start at a highlighted sequence position on a lifeline, then click or drag to the receiving lifeline. The form retains the chosen position while you select the exchange and details. Escape cancels the gesture.",
+                                "Choose a message style in the tool selector. Start at a highlighted sequence position on a lifeline, then click or drag to the receiving lifeline. Complete the exchange and details in the form, which retains that sequence position. Escape cancels the gesture.",
+                                "Call + correlated reply creates both occurrences in one edit. Reply to existing call offers valid unanswered calls. A local timer has an expression and a lifeline, with no global exchange. Create and delete messages describe participant lifetime; Model checks also flag risks inside repeated loops.",
+                                "Choose Add action, Observe state, Reuse scenario or Add fragment and click the intended sequence position. Clicking an action or observation on a lifeline also selects that lifeline. Complete any remaining choices before Create.",
                                 "In Select / reorder, click an occurrence and drag its ↕ handle to another position within the same sequence. The ordered list's up/down controls provide another way to reorder. Select an occurrence to inspect its particular use of the exchange, including its message values.",
                             ],
                         ),
                         walkthrough(
                             "Describe alternatives",
                             &[
-                                "Choose Fragment and select ALT, PAR, LOOP or OPT. Enter the branch conditions; the tool creates the fragment and its operands together.",
-                                "Use the Destination selector in subsequent message or action forms to choose the intended operand. New occurrences append to that operand's ordered behavior.",
-                                "Use Reuse scenario to refer to existing behavior. Bind every referenced lifeline to a compatible local lifeline explicitly. Open source follows the original scenario without copying its contents.",
+                                "Choose Add fragment, click its sequence position and select ALT, PAR, LOOP or OPT. Enter the branch conditions; the tool creates the fragment and its operands together.",
+                                "Click the highlighted position inside an operand to place the next message, action or reference there. The form shows its destination and insertion position. Append to this sequence instead explicitly moves the pending insertion to that sequence's end.",
+                                "Choose Reuse scenario and click its position, then bind every referenced lifeline to a compatible local lifeline explicitly. Select the resulting use and choose Open definition. Back to caller returns to that exact use and its viewport after you apply or cancel pending edits.",
                                 "Inspect the scenario projection and Model checks. State exactly what each guard means, including units and assumptions where relevant.",
                             ],
                         ),
@@ -696,6 +696,10 @@ fn article(topic: Topic) -> Article {
                             "Map references by meaning",
                             "Reference mapping connect exact OA and SA identities used by the proposed change. Similar names are not sufficient. Map the records that play the same engineering role, including enclosing fields in qualified message-value paths. Mapping a referenced record does not authorize creating, moving or editing that record. If it needs a counterpart, establish that correspondence first.",
                         ),
+                        explain(
+                            "Edit stored observations deliberately",
+                            "In a trace's Properties, Edit stored history (advanced)… edits the observations retained by that trace. Choose the fact and enter its Operational and System observations explicitly. Not applicable, an observed absent value, and no stored fact have different meanings. Historical references may retain the exact UUID of a deleted record. Apply changes validates the complete history; Undo restores it. These history edits leave both counterpart records unchanged. Use Review counterpart changes… for Keep/Take decisions about their current engineering content.",
+                        ),
                         walkthrough(
                             "Review one message value or lifeline binding",
                             &[