implement the includeCoAuthoredBy option

[CodinCat]

let me know if you want to merge this. I'll resolve the conflicts
and feel free to just close this PR if you don't want this to be added.

---

fix #919

Add the include_co_authored_by option. The behavior is copied from Claude Code.

When it's true (default) the prompt remains unchanged. I copied the original prompt and verified it with a temporary test:

test("bash.txt", () => {
  const bashTxtPath = join(process.cwd(), "packages/opencode/src/tool/bash-backup.txt")
  const currentContent = readFileSync(bashTxtPath, "utf-8")
  expect(replaceCoAuthoredMessage()).toBe(currentContent)
})

And this is how the three places look when it's false. This should be the same as Claude Code:

1

2

3

---

actual usage:

true:

false:

[CodinCat]

no changes below. just indentation.

the actual diff:

[samholmes]

Personally I'd prefer the replacing technique where you section the cases out in the .txt file using some line deliminters

3. You have the capability to call multiple tools in a single response. When multiple independent pieces of information are requested, batch your tool calls together for optimal performance. ALWAYS run the following commands in parallel:
   - Add relevant untracked files to the staging area.
<<with-co-author>>
   - Create the commit with a message ending with:
   🤖 Generated with [opencode](https://opencode.ai)

   Co-Authored-By: opencode <[email protected]>
<</with-co-author>>
<<without-co-author>>
   - Create the commit with a message
<</without-co-author>>
   - Run git status to make sure the commit succeeded.

Then some utilities can be written and tested for to keep/select/remove these sections.

Pros:

• All of the text remains in the .txt file (not in the codebase)
• Code handling these sections can be clear to understand given the utilities are defined

Cons:

• A little more complexity and abstraction, but easily managed with some utility functions.

[dbirks]

Can confirm this works nicely, thanks!

[samholmes]

Can confirm this works nicely, thanks!

An alternative implementation which leverages no custom templating system and instead opts in for using mustache: #1430