feat(workflows): drop the Tool Execution Flow sankey

The d3-sankey tool-transition chart was the last of the deep harness-internals
visualizations issue #6 set out to remove: a wall of bands showing that Read
tends to precede Edit, with nothing a reader could act on. It goes, along with
its i18n keys in both locales and the now-orphaned d3-sankey dependency.

The workflows API response is untouched — `toolFlow` still ships in the
aggregate and still feeds the Dashboard's top-tools list. Remaining sections
renumber 4-9.

client/src/pages/Workflows.tsx

@@ -3,10 +3,10 @@
  * @description Workflows page. Opens on this dashboard's OWN pipelines — per-node
  * pass rates across every lane, and which skills/plugins actually get used — then
  * the Claude Code orchestration analytics: headline stats, Workflow-tool runs, the
- * spawning DAG, tool flow, patterns, model delegation, error propagation, session
- * complexity, compaction impact and the per-session drill-in. Issue #6 dropped the
- * agent collaboration network and the subagent effectiveness scorecards as too
- * specialized to act on.
+ * spawning DAG, patterns, model delegation, error propagation, session complexity,
+ * compaction impact and the per-session drill-in. Issue #6 dropped the agent
+ * collaboration network and the subagent effectiveness scorecards as too
+ * specialized to act on; the tool-execution Sankey followed for the same reason.
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
 /* =============================================================================
@@ -35,7 +35,6 @@
  * - `../components/workflows/SkillUsagePanel`
  * - `../components/workflows/WorkflowRunsPanel`
  * - `../components/workflows/OrchestrationDAG`
- * - `../components/workflows/ToolExecutionFlow`
  * - `../components/workflows/WorkflowPatterns`
  * - `../components/workflows/ModelDelegationFlow`
  * - `../components/workflows/ErrorPropagationMap`
@@ -82,7 +81,6 @@ import type { WorkflowData, WSMessage } from "../lib/types";
 
 import { WorkflowStats } from "../components/workflows/WorkflowStats";
 import { OrchestrationDAG } from "../components/workflows/OrchestrationDAG";
-import { ToolExecutionFlow } from "../components/workflows/ToolExecutionFlow";
 import { WorkflowPatterns } from "../components/workflows/WorkflowPatterns";
 import { ModelDelegationFlow } from "../components/workflows/ModelDelegationFlow";
 import { ErrorPropagationMap } from "../components/workflows/ErrorPropagationMap";
@@ -267,19 +265,9 @@ export function Workflows() {
         )}
       </Section>
 
-      {/* Section 4: Tool Execution Flow */}
+      {/* Section 4: Workflow Patterns */}
       <Section
         number={4}
-        title={t("toolFlow.title")}
-        subtitle={t("toolFlow.subtitle")}
-        infoKey="toolFlow"
-      >
-        <ToolExecutionFlow data={data.toolFlow} filterAgentType={selectedNode} />
-      </Section>
-
-      {/* Section 5: Workflow Patterns */}
-      <Section
-        number={5}
         title={t("patterns.title")}
         subtitle={t("patterns.subtitle")}
         infoKey="patterns"
@@ -287,10 +275,10 @@ export function Workflows() {
         <WorkflowPatterns data={data.patterns} onPatternClick={() => {}} />
       </Section>
 
-      {/* Section 6 + 7: Two Column */}
+      {/* Section 5 + 6: Two Column */}
       <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">
         <Section
-          number={6}
+          number={5}
           title={t("modelDelegation.title")}
           subtitle={t("modelDelegation.subtitle")}
           infoKey="modelDelegation"
@@ -299,7 +287,7 @@ export function Workflows() {
         </Section>
 
         <Section
-          number={7}
+          number={6}
           title={t("errorPropagation.title")}
           subtitle={t("errorPropagation.subtitle")}
           infoKey="errorPropagation"
@@ -308,10 +296,10 @@ export function Workflows() {
         </Section>
       </div>
 
-      {/* Section 8 + 9: Two Column */}
+      {/* Section 7 + 8: Two Column */}
       <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">
         <Section
-          number={8}
+          number={7}
           title={t("complexity.title")}
           subtitle={t("complexity.subtitle")}
           infoKey="complexity"
@@ -320,7 +308,7 @@ export function Workflows() {
         </Section>
 
         <Section
-          number={9}
+          number={8}
           title={t("compaction.title")}
           subtitle={t("compaction.subtitle")}
           infoKey="compaction"
@@ -329,9 +317,9 @@ export function Workflows() {
         </Section>
       </div>
 
-      {/* Section 10: Session Drill-In */}
+      {/* Section 9: Session Drill-In */}
       <Section
-        number={10}
+        number={9}
         title={t("drillIn.title")}
         subtitle={t("drillIn.subtitle")}
         infoKey="drillIn"