feat(dashboard): add entity detail modal and fixed-layout tables

Replace Inputs.table() with buildEntityTable() across workstreams and
tasks pages. Add click-to-detail modal (openEntityModal) on all entity
list views: workstreams, tasks, extension points, and technical debt.

- New component: src/components/entity-modal.js
  - openEntityModal(entity, type) — full-detail overlay (Esc/click-outside to close)
  - buildEntityTable(rows, cols, onRowClick) — table-layout:fixed, overflow-safe wrapper
  - CSS injected lazily; no separate stylesheet required

- Tables: table-layout:fixed keeps content within the content column;
  title col 32%, workstream col 14%, all cells ellipsis + title tooltip
- Cards (EP, TD): onclick → modal; workstream name span gets title tooltip
- Blocked task cards also wired to modal

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

dashboard/src/workstreams.md

@@ -132,9 +132,10 @@ const _domainBreakdown = [...new Set(openWs.map(w => _idToDomain[w.id] ?? "unkno
 # Workstreams
 
 ```js
-import {injectTocTop} from "./components/toc-sidebar.js";
-import {withDocHelp}   from "./components/doc-overlay.js";
-import                      "./components/help-tip.js";
+import {injectTocTop}    from "./components/toc-sidebar.js";
+import {withDocHelp}     from "./components/doc-overlay.js";
+import                        "./components/help-tip.js";
+import {openEntityModal, buildEntityTable} from "./components/entity-modal.js";
 
 // ── Live indicator ────────────────────────────────────────────────────────────
 const _liveEl = html`<div class="live-indicator">
@@ -270,14 +271,24 @@ display(Plot.plot({
 ```js
 display(_filtersForm);
 
-display(Inputs.table(filtered.map(w => ({
-  Title:   w.title,
-  Domain:  w.domain,
-  Status:  w.status,
-  Owner:   w.owner ?? "—",
-  Due:     w.due_date ?? "—",
-  Updated: new Date(w.updated_at).toLocaleDateString(),
-})), {rows: 20}));
+{
+  // Enrich each workstream with tasks/deps data from open_workstreams summary
+  const _openWsMap = Object.fromEntries(openWs.map(w => [w.id, w]));
+  const _wsTable = buildEntityTable(
+    filtered,
+    [
+      {label: "Title",   key: "title",   cls: "et-title-col et-title-cell",
+       render: w => w.title},
+      {label: "Domain",  key: "domain"},
+      {label: "Status",  key: "status"},
+      {label: "Owner",   render: w => w.owner ?? "—"},
+      {label: "Due",     render: w => w.due_date ?? "—"},
+      {label: "Updated", render: w => new Date(w.updated_at).toLocaleDateString()},
+    ],
+    w => openEntityModal({...w, ..._openWsMap[w.id]}, "workstream"),
+  );
+  display(_wsTable);
+}
 ```
 
 ## Dependencies