feat(tasks): phase 6 — live TaskContextPanel (goal, plan, question, entities)

Replaces the chat right rail's ad-hoc Digest+Graph stack with a single
TaskContextPanel that renders the task's live working state, driven by the
always-on events stream (not the per-turn chat SSE) so it keeps updating
during server-side auto-continuation/resume:

- GoalHeader: goal + status pill (planning/executing/awaiting_input/done/
  failed), sourced from the sessions list.
- PlanProgress: ordered steps with live status icons + progress bar, hydrated
  via new GET /sessions/{id}/plan; clicking a step with a target opens its
  EntitySheet (no fake "jump to transcript" — bits-ui Collapsible content
  isn't force-mounted, so a DOM-scroll jump would silently no-op for
  collapsed tool groups).
- OperatorQuestion: the pinned structured question card (prompt/why/entity
  chips/option buttons/free-text), hydrated via new GET /sessions/{id}/
  questions; answering POSTs to the existing answer endpoint.
- SessionGraph upgraded to a live entity panel: entity.touched pulses the
  node (animated ring) and shows "Now touching <slug>"; health.changed shows
  a transient diff badge for touched entities.
- SessionDigest gains a success/failure/partial outcome banner and now also
  refetches when the task's status changes, not just on session switch.

Two bugs found and fixed while wiring this up:
- workspace.ts's status-refresh trigger only covered goal.set/task.status;
  question.raised/answered didn't refresh the sessions list, so GoalHeader's
  pill went stale after answering via the panel (resumeSession runs entirely
  server-side — no client 'done' event to piggyback a refresh on). Now every
  status-affecting event triggers the (debounced) refetch.
- Forgot to rebuild the nomos container after adding the /plan and
  /questions endpoints, so they silently fell through to the old default GET
  handler — caught via a live curl diff against the running container,
  not a code read.

Verified end-to-end against the live stack: goal/plan/question all update
without a reload as the agent works; answering a question via the panel
resumes the agent and the header pill correctly flips to Executing;
entity.touched pulses the live graph.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/src/lib/components/SessionGraph.svelte

@@ -12,6 +12,7 @@
   } from 'd3-force'
   import { fetchGraph, type Entity } from '$lib/api'
   import { messages } from '$lib/stores/chat'
+  import { touched, healthDiffs } from '$lib/stores/workspace'
   import { relativeTime } from '$lib/utils'
   import { Badge } from '$lib/components/ui/badge'
   import { Button } from '$lib/components/ui/button'
@@ -226,6 +227,21 @@
     return slug.split(':').pop() ?? slug
   }
 
+  // Live touch/health-diff lookups, keyed by slug for O(1) per-node checks
+  // during render. Kept as plain objects (not Maps) since Svelte 5 runes track
+  // object identity fine and this is small (≤12 touched, ≤8 diffs).
+  const touchedBySlug = $derived.by(() => {
+    const m: Record<string, true> = {}
+    for (const t of $touched) m[t.slug] = true
+    return m
+  })
+  const diffBySlug = $derived.by(() => {
+    const m: Record<string, { from: string; to: string }> = {}
+    for (const d of $healthDiffs) if (!(d.slug in m)) m[d.slug] = d
+    return m
+  })
+  const nowTouching = $derived($touched[0] ?? null)
+
   function endpoint(end: string | Node): Node | undefined {
     return typeof end === 'object' ? end : nodes.find((n) => n.slug === end)
   }
@@ -290,6 +306,12 @@
       <span class="text-[11px] text-muted-foreground">{nodes.length} {nodes.length === 1 ? 'entity' : 'entities'}</span>
     {/if}
   </div>
+  {#if nowTouching}
+    <div class="flex shrink-0 items-center gap-1.5 border-b bg-primary/5 px-3 py-1.5 text-[11px] text-primary">
+      <span class="size-1.5 animate-pulse rounded-full bg-primary"></span>
+      Now touching <code class="font-mono">{nowTouching.slug}</code>
+    </div>
+  {/if}
 
   <div bind:this={container} class="relative min-h-0 flex-1 overflow-hidden">
     {#if nodes.length === 0}
@@ -353,6 +375,8 @@
               {@const r = nodeRadius(node)}
               {@const isSel = selected?.slug === node.slug}
               {@const dim = selected && !isSel && !selectedRelations.some((rel) => rel.other === node.slug)}
+              {@const isTouched = node.slug in touchedBySlug}
+              {@const diff = diffBySlug[node.slug]}
               <g
                 transform="translate({node.x},{node.y})"
                 class="cursor-pointer"
@@ -365,6 +389,12 @@
                 {#if isSel}
                   <circle r={r + 5} fill={nodeColor(node)} opacity="0.25" />
                 {/if}
+                {#if isTouched}
+                  <circle r={r + 4} fill="none" stroke="var(--primary)" stroke-width="1.5" opacity="0.8">
+                    <animate attributeName="r" values="{r + 3};{r + 8};{r + 3}" dur="1.6s" repeatCount="indefinite" />
+                    <animate attributeName="opacity" values="0.8;0.1;0.8" dur="1.6s" repeatCount="indefinite" />
+                  </circle>
+                {/if}
                 <circle r={r} fill={nodeColor(node)} stroke={isSel ? 'var(--foreground)' : 'var(--background)'} stroke-width={isSel ? 2 : 1.5} />
                 <text
                   y={r + 10}
@@ -378,6 +408,20 @@
                 >
                   {shortName(node.slug)}
                 </text>
+                {#if diff}
+                  <text
+                    y={-r - 6}
+                    text-anchor="middle"
+                    font-size="8"
+                    fill="var(--warning)"
+                    paint-order="stroke"
+                    stroke="var(--background)"
+                    stroke-width="2.5"
+                    class="pointer-events-none"
+                  >
+                    {diff.from} → {diff.to}
+                  </text>
+                {/if}
               </g>
             {/if}
           {/each}