chore(baseline): target DSH 0.1.6-alpha.2 and drop 0.1.5-rc support

The peer floor had to move: semver's prerelease rule needs a comparator on the
same [major,minor,patch] tuple, so `^0.1.5-rc.1` can never match any 0.1.6
prerelease. The floor becomes `^0.1.6-alpha.2` (which does admit 0.1.6 alpha/rc
prereleases and excludes 0.1.5), and `engines.dsh` follows. This is a deliberate
support-line break, matching how v0.19.0 dropped 0.1.2: 0.1.5-rc hosts stay on
0.19.1.

Three upstream changes actually reach this plugin and are adapted here:

- `IconSendOutline16` no longer exists in ui-primitives (only
  `IconSendOutline14`).
- `TerminalBlockLabels` gained a required `noExitCode` pill text.
- `ConnectionIndicator` dropped `reconnectLabel`: the outage label is now the
  one static label that already names the retry action, so the label copy moves
  there, matching the host's own '连接异常，点击立即重连'.

ui-primitives still declares no `dependencies` while its bundle bare-imports
more than it used to: `diff` and `simple-icons` were previously satisfied only
transitively and had to be hoisted into devDependencies, exactly like the
anser/shiki/katex group before them. `@deepseek-ai/dsh-code-runtime` is gone
upstream (the package no longer exists) and leaves the dev tree.

The e2e fallback npx spec is pinned rather than version-less: an unpinned
`npx @deepseek-ai/dsh` resolves npm's `latest`, which is still the 0.1.5 line
this plugin no longer supports.

src/client/SideChatView.tsx

@@ -36,7 +36,7 @@ import {
   IconNewChatOutline16,
   IconPlusOutline16,
   IconSearchOutline16,
-  IconSendOutline16,
+  IconSendOutline14,
   IconSparkle16,
   IconStopFill16,
   MarkdownText,
@@ -354,6 +354,9 @@ export function SideChatView(props: {
         ...shared,
         signal: (signal: string) => t('sideChatBlockSignal', { signal }),
         exitCode: (exitCode: number) => t('sideChatBlockExitCode', { code: exitCode }),
+        // DSH 0.1.6-alpha.2 added this pill text: a settle the view cannot
+        // name (killed by an unknown signal, or never started).
+        noExitCode: t('sideChatBlockNoExitCode'),
         running: t('sideChatBlockRunning'),
         failed: t('sideChatBlockFailed'),
         done: t('sideChatBlockDone'),
@@ -739,7 +742,6 @@ export function SideChatView(props: {
         <ConnectionIndicator
           state={connectionState}
           disconnectedLabel={t('sideChatConnDisconnected')}
-          reconnectLabel={t('sideChatConnReconnect')}
           connectingLabel={t('sideChatConnConnecting')}
           recoveredLabel={t('sideChatConnRecovered')}
           reconnectActionLabel={t('sideChatConnReconnectAction')}
@@ -802,7 +804,7 @@ export function SideChatView(props: {
               disabled={composer.trim() === '' || busy !== null}
               title={t('sideChatSend')}
             >
-              <IconSendOutline16 />
+              <IconSendOutline14 size={16} />
             </button>
           )}
         </div>