Read comment content from stdin when using dash

[robzolkos]

Fix comment creation and updates so using - reads the comment body from stdin instead of posting a literal dash. This supports the heredoc workflow reported from the Agent Accessibility card and prevents silent wrong-comment posts.

Related: #414 covers implicit piped stdin when comment creation omits positional content; this PR covers the explicit - stdin convention and also applies it to comment updates. The two changes complement each other but will need a small reconciliation if both land.

Ref: https://3.basecamp.com/2914079/buckets/46292715/card_tables/cards/9890985489

[Copilot]

Pull request overview

Adds support for reading comment content from stdin when - is passed as the content argument to basecamp comment and basecamp comments update, enabling heredoc/pipe workflows and preventing accidental posts of a literal dash.

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Changes:

• Introduces helper contentArgOrStdin that reads from cmd.InOrStdin() when args is a single -.
• Wires the helper into both the create (basecamp comment) and update (basecamp comments update) commands; updates help text with stdin examples.
• Adds tests verifying stdin content is sent in the request body (not a literal dash) for both commands.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
internal/commands/comment.go	Adds contentArgOrStdin helper, uses it in create/update RunE, and extends help examples.
internal/commands/comment_test.go	Adds mock transport + tests asserting stdin content is sent for create and update.

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[cubic-dev-ai]

1 issue found across 2 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="internal/commands/comment.go">

<violation number="1" location="internal/commands/comment.go:327">
P2: `create` reads stdin for `-` before enforcing the `--edit` conflict, so `--edit` + `-` can hang waiting on stdin instead of failing fast.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[robzolkos]

Fixed — cubic found that --edit + - could read stdin before failing; the create command now rejects positional content with --edit before stdin handling.