fix(web): address the review round on the remaining context forms

- `relay` resolves its sender in `contextBody` like every other form. It was
  the one shape whose marker could claim a form the body did not render: an
  unreadable sender fell back inside the body while the row still said relay,
  contradicting the contract this PR's own note states.
- `recall` requires the retained, omitted, and truncated fields. Completeness
  is what the card exists to report, so a reference that cannot state it is
  not a readable recall — showing the label alone presents a confident card
  over unknown loss.
- The snapshot body states the supersession its producer framing line carries.
  That line is the one part of the model-facing text no section contains, and
  unlike an instruction context's `<system-reminder>` it states the form's own
  semantics rather than wrapping content.
- `GoalMessageSource` is a discriminated pair, so `{ form: 'notice' }` without
  its account no longer compiles. The guarantee this PR claims now holds at
  that seam too, not only through `ContextFormed` on plugin sources.
- Goal and tool-goal summaries are bounded by a shared `boundContextSummary`,
  which tool-tasks now uses as well. A goal objective is unbounded caller text
  in exactly the way a task label is.
- The runtime snapshot interpolates once per request: agent-loop renders the
  sections and joins them through `joinContextSections`.
- Every form's fallback branch is pinned, not only the notice one.

packages/goal/tool-goal/src/index.ts

@@ -8,7 +8,7 @@ import type { Context } from 'cordis'
 import z from 'schemastery'
 import { GoalId } from '@deepseek-ai/dsh-goal'
 import type { GoalRef, GoalView } from '@deepseek-ai/dsh-goal'
-import { createUserMessage, HarnessError } from '@deepseek-ai/dsh-llm'
+import { boundContextSummary, createUserMessage, HarnessError } from '@deepseek-ai/dsh-llm'
 import { defineTool } from '@deepseek-ai/dsh-tools'
 import type { GenericCallView } from '@deepseek-ai/dsh-tools'
 import type {} from '@deepseek-ai/dsh-system-prompt'
@@ -319,7 +319,7 @@ export function apply(ctx: Context, config: Config): void {
             kind: 'plugin',
             plugin: 'tool-goal',
             form: 'notice',
-            summary: `${args.action as string}: ${goal.objective}`,
+            summary: boundContextSummary(`${args.action as string}: ${goal.objective}`),
           },
         }))
       }