feat: adapt to DSH 0.1.7-alpha.1 and yield the read-only previews

DSH 0.1.7-alpha.1 is 1299 commits past 0.1.6-alpha.2 and rewrites four
contracts this plugin was built on. The peer floor moves to
^0.1.7-alpha.1 (semver's prerelease rule means ^0.1.6-alpha.2 can never
match a 0.1.7 prerelease); 0.1.6-alpha.2 and earlier stay on v0.19.1.
Released as 0.21.0-alpha.1 (dist-tag alpha).

Hard breaks:
- dsh-settings was rewritten: register(ns, schema) is gone, a form is
  addressed by the plugin row's Loader entry id and read from the
  module's exported Config. The preferences are merged into Config and
  marked volatile — which requires DSH's own schemastery, because only
  that build wraps a volatile field in the cosmokit reference the
  loader's volatile commit walks. With the public package a settings
  write reports success and revision 1 while the effective value never
  changes.
- ui-primitives renamed its whole icon family (IconXxx14/16 ->
  IconXxxRegular/Medium): 26 imported symbols, 17 files. The failing
  mode is render-time, not load-time. Five call sites that relied on the
  old 14px default now pass size={14} explicitly.
- Session format v4 rejects source.kind === 'plugin'; the side-chat
  boundary injection now writes plugin:dsh-better-sidebar, the same kind
  DSH's own v3->v4 migration produces, so historical threads survive.
  Tool results moved to role 'tool' with top-level content/isError; all
  four parsers accept both shapes.
- The client session snapshot dropped subagentsByParent/jobsBySession
  and the on-demand subagent-catalog observation API. The Tasks page
  reads projectionsBySession and a new jobs.list route.

Yields and convergence:
- The read-only previews go to DSH's documentpreview (Office->PDF, a
  spreadsheet worker, zoom, per-directory refresh); editor.canOpen
  refuses those 26 extensions. Markdown, HTML (with its sandbox
  switches) and the editable code buffer stay.
- The host browser kind is desktop-profile-only now, so the web e2e
  lanes expect no browser entry and assert its absence.
- Link takeover claims only urlTarget links and passes the rest to the
  host, fixing a regression from the 0.1.6 round: the fallback pointed
  at a 'browser' type the plugin no longer registers, so http links in
  its own markdown did nothing.

Also fixed, found along the way:
- The file tree refreshes live (new directory watch over the plugin's
  own socket), since the plugin owns the `files` kind.
- ctx.sessions.list has no `current` field at either tag; the three
  readers were dead. They now use ctx.sidebarRight.mounted.
- package.json.files was missing lib/client-locale.js.
- Two genuinely dead call sites: sessions.openSubagent/open/
  refreshSubagents do not exist on the current baseline, so the
  topology click, the jump-back and the retry were all no-ops.
- The test harness window shim lacked addEventListener, which the 0.1.7
  primitives call at module-evaluation time; and the e2e token exchange
  needs Playwright's request stack, not Node's fetch.

tests/changes-ops.spec.ts

@@ -4,6 +4,7 @@
  * (their full behavior suites live in the standalone dsh-file-trace plugin).
  */
 import { describe, expect, it } from 'vitest'
+import { createToolResultMessage, ToolCallId } from '@deepseek-ai/dsh-llm'
 import { extractFileOps, groupByFile, knownContentBefore, parseReadContent, parseReadLines } from '../src/client/changes/ops.ts'
 import { diffLines, buildDiffSegments, coalesceInline, diffInline } from '../src/client/diff/rows.ts'
 import { langOfPath, scanLine } from '../src/client/diff/highlight.ts'
@@ -19,10 +20,26 @@ function call(seq: number, name: string, callId: string, args: unknown, time = s
   return ev('tool/call', seq, time, { name, callId, arguments: JSON.stringify(args) })
 }
 
-/** A tool/result event carrying one tool-result block with inner text. */
+/** A tool/result event carrying one first-class tool-role message (the 0.1.7
+ *  shape: result blocks and `isError` at the message's own top level). */
 function result(seq: number, callId: string, text: string, isError = false, time = seq): SidebarSessionEvent {
   return ev('tool/result', seq, time, {
     message: {
+      role: 'tool',
+      source: { kind: 'tool', callId },
+      toolCallId: callId,
+      isError,
+      content: [{ type: 'text', text }],
+    },
+  })
+}
+
+/** The retired 0.1.6 shape: a role-'user' message wrapping the result in one
+ *  `tool-result` content block. Historical logs still carry it. */
+function legacyResult(seq: number, callId: string, text: string, isError = false, time = seq): SidebarSessionEvent {
+  return ev('tool/result', seq, time, {
+    message: {
+      role: 'user',
       source: { kind: 'tool', callId },
       content: [{ type: 'tool-result', isError, content: [{ type: 'text', text }] }],
     },
@@ -96,6 +113,32 @@ describe('extractFileOps', () => {
     expect(ops.map(op => op.callId)).toEqual(['r'])
   })
 
+  it('reads the tool/result message dsh-llm actually produces (producer round-trip)', () => {
+    const message = createToolResultMessage({
+      callId: ToolCallId('r'),
+      content: [{ type: 'text', text: 'produced file body' }],
+      isError: false,
+    })
+    const ops = extractFileOps([
+      call(1, 'read', 'r', { file_path: 'a.ts' }),
+      ev('tool/result', 2, 2, { message: message as unknown as Record<string, unknown> }),
+    ])
+    expect(ops[0]!.running).toBe(false)
+    expect(ops[0]!.read).toBe('produced file body')
+  })
+
+  it('reads a LEGACY 0.1.6-era tool-result wrapper (historical logs keep that shape)', () => {
+    const ops = extractFileOps([
+      // No content in the model's arguments, so the settled result supplies it.
+      call(1, 'write', 'w', { file_path: 'a' }),
+      legacyResult(2, 'w', 'legacy write detail'),
+      call(3, 'read', 'r', { file_path: 'b' }),
+      legacyResult(4, 'r', 'cannot read "b": not found', true),
+    ])
+    expect(ops.find(op => op.kind === 'write')?.content).toBe('legacy write detail')
+    expect(ops.find(op => op.kind === 'read')?.errorText).toBe('cannot read "b": not found')
+  })
+
   it('groups by file newest-first and recovers prior write content', () => {
     const ops = extractFileOps([
       call(1, 'write', 'w1', { file_path: 'a.ts', content: 'first' }),