fixtures: golden data dir — real records, production read paths

Owner-manufactured teach master (chat_mv27rrra: compaction, subagent-abort,
every teach tool) + practice lifecycle (chat_mv293wv5: the full marker cycle
including the first-ever problem-dismissed), the real graph ledgers, five
jobs across the kind x status matrix, and settings. tests/golden-fixtures
reads all of it through the stores via the LH_DATA_DIR seam and pins the
fixture law: real data parses, flattens to a legal LLM wire, derives the
graph, covers every custom-marker kind, and reads never write.

Fixture law: an intentional format change updates these files in the same
commit; an unintentional one fails the suite.

tests/fixtures/golden-data/graph/render-settings.json

@@ -0,0 +1,29 @@
+{
+	"sizeUnits": "world",
+	"nodeSize": 2,
+	"edgeWidth": 1,
+	"arrowLength": 2,
+	"labelZoom": 0.5,
+	"labelSize": 3,
+	"clusterLabels": true,
+	"clusterLabelSize": 14,
+	"regions": {
+		"dilation": 20,
+		"blur": 40,
+		"bitmap": 384,
+		"edgeAlpha": 0.2,
+		"enabled": true
+	},
+	"physics": {
+		"chargeStrength": -240,
+		"linkStrength": 1,
+		"linkDistance": 40,
+		"gravity": 0.12,
+		"clusterPull": 0.15,
+		"velocityDecay": 0.4,
+		"depthMode": "vertical",
+		"depthStrength": 0.8,
+		"depthSpacing": 60,
+		"depthBaseRadius": 220
+	}
+}