experiment: replace landing with workshop introduction

- Added Welcome card (Before we begin) to idle state
- Reduced textarea from 10 to 6 rows
- Added reassurance text below Analyse button
- Removed redundant empty-state placeholder
- Closed Experiment 03 (Partially confirmed) in evolution log
- Added Experiment 04: Facilitated Workshop Introduction
- Added Entry Experience section to UX guidelines

docs/design-evolution-log.md

@@ -198,7 +198,64 @@ Map
 Separating these should make the interface feel more like a facilitated investigation than a collection of cards.
 
 Evaluation:
-Pending visual review.
+Partially confirmed.
+
+Learning:
+
+The workspace feels more coherent when organised into cognitive zones rather than a simple document stack.
+
+However, another distinction emerged that is more important than the zones themselves.
+
+The interface naturally separates into two different modes:
+
+• the active conversation between investigator and facilitator
+
+and
+
+• the shared workspace describing the current understanding.
+
+Unexpected learning:
+
+History feels incorrect when treated as reference information.
+
+History is actually the continuation of the investigator's conversation.
+
+Every response immediately becomes history.
+
+The notebook should therefore grow naturally from the Response area.
+
+The Investigation Status card currently competes with the Current Investigation card.
+
+The current question is the primary focus.
+
+Status is supporting context.
+
+Decision:
+
+Keep the cognitive-zone concept.
+
+Refine the zones around conversational flow instead of card grouping.
+
+Next question:
+Can the workspace clearly separate conversation from shared understanding?
+
+### Experiment 04 — Facilitated Workshop Introduction
+
+Hypothesis
+
+Beginning with a facilitator-style introduction will create more confidence than presenting an empty workspace.
+
+Questions
+
+- Does the interface feel more welcoming?
+- Does reducing the visual weight of the textarea improve the first experience?
+- Does separating "starting" from "investigating" feel natural?
+- Does the transition into the investigation workspace feel meaningful?
+
+Status:
+Experimental.
+
+No conclusions.
 
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