Navie pinned prompt can include option flags

As a user, I may want to create a predefined prompt and load it into my Navie session using the Pin feature.

The prompt may begin with Navie options, and if present, these are respected.

To be applied, Navie options must be on the first line of the prompt; just like when asking a question.

Example:

This prompt will split a diff into logical chunks. Project context is not required, so the /nocontext option is specified.

changes.md

/nocontext

Inspect the diff and create a logical changes that were made to the code.

Emit the list as a Markdown list, with a title and paragraph. Each change should should print the
diff hunks that relate to that change within markdown fences in the section.

Example:

- First change

The first change was to add a new line at the end of the file.

\`\`\`diff
@@ -1,2 +1,3 @@
  This is a file.
  It has some content.
+ This is a new line.
\`\`\`

- Second change

The second change was to remove a space at the beginning of the file.

\`\`\`diff
@@ -1,2 +1,2 @@
- This is a file.
+This is a file.
  It has some content.
\`\`\`

Start by tracing the Navie Pin feature and the code that parses options from a question's first line. Check how pinned prompts are loaded into a Navie session, then verify that options at the beginning of a pinned prompt are applied while later options are not. Done means the provided /nocontext example behaves as described.