fix(site): docker run command was malformed when secret path enabled

The docker-deployment branch built a one-line `docker run` command but
constructed the secret-path fragment with a trailing `\<newline>`
(intended as a shell-line-continuation) and then `.trim()`-ed only the
newline before splicing it back into the same line. The trailing
backslash survived into the rendered command:

    ... -e MCP_SECRET_PATH=/private_xxx \ ghcr.io/...

Bash parses `\<space>` as an escaped space, joining the leading
whitespace onto the next token — so docker was invoked with an image
argument of " ghcr.io/homeassistant-ai/ha-mcp:latest" (note the leading
space), which fails with `invalid reference format`. Users who
enabled the secret path on the Docker deployment got a broken
copy-paste command.

Drop the trailing `\\\n` from secretPathEnv (no continuation needed
inline) and remove the matching .trim() at the splice site. The
emitted command is now:

    docker run -d --name ha-mcp -p 8086:8086 -e ... -e ... -e MCP_SECRET_PATH=/private_xxx ghcr.io/...

Pre-existing bug in master (predates homeassistant-ai#1106). Boy Scout fix bundled
here since the surrounding deployment block is being heavily touched
by this PR.

Build verified clean (npm run build, 7 pages, 41s).

Author: kingpanther13

site/src/pages/setup.astro

@@ -1322,15 +1322,15 @@ ${secretPathEnv}uvx --from ha-mcp@latest ha-mcp-web</code></pre>
         }
       } else if (derivedDeployment === 'docker') {
         const useSecretPath = isRemote && state.proxy !== 'webhook-proxy';
-        const secretPathEnv = useSecretPath ? `  -e MCP_SECRET_PATH=/private_{{RANDOM_STRING}} \\\n` : '';
+        const secretPathEnv = useSecretPath ? `-e MCP_SECRET_PATH=/private_{{RANDOM_STRING}}` : '';
         const serverPath = useSecretPath ? '/private_{{RANDOM_STRING}}' : '/mcp';
         const dockerPortNote = `<p class="text-xs text-slate-500 mt-2">Optional: Change <code>-p 8086:8086</code> to use a different port (e.g., <code>-p 9000:8086</code>).</p>`;
         const composeSecretPathLine = useSecretPath
           ? `\n      - MCP_SECRET_PATH=/private_{{RANDOM_STRING}}`
           : '';
         deployInstr = `<div class="instruction-block">
           <h4 class="instruction-title">Start Docker Container</h4>
-          <pre class="code-block"><code>docker run -d --name ha-mcp -p 8086:8086 -e HOMEASSISTANT_URL={{HOMEASSISTANT_URL}} -e HOMEASSISTANT_TOKEN={{HOMEASSISTANT_TOKEN}}${secretPathEnv ? ' ' + secretPathEnv.trim() : ''} ghcr.io/homeassistant-ai/ha-mcp:latest ha-mcp-web</code></pre>
+          <pre class="code-block"><code>docker run -d --name ha-mcp -p 8086:8086 -e HOMEASSISTANT_URL={{HOMEASSISTANT_URL}} -e HOMEASSISTANT_TOKEN={{HOMEASSISTANT_TOKEN}}${secretPathEnv ? ' ' + secretPathEnv : ''} ghcr.io/homeassistant-ai/ha-mcp:latest ha-mcp-web</code></pre>
           <p class="text-sm text-slate-400 mt-2">Server will be at: <code>http://YOUR_IP:8086${serverPath}</code></p>${dockerPortNote}${secretPathNote}
           <details class="mt-3">
             <summary class="cursor-pointer text-sm text-slate-300 font-medium hover:text-slate-100">Production hardening (docker compose)</summary>