I can reply to a pitch without leaving the dashboard

[jamescrosswell]

Context

Yes is one of two answers to a pitch. The other — not yet, because… — still means a browser today.
This slice adds it to the reader, and with it the way you ask for a pitch to be shelved: the Lead is
already required to move a pitch back to Idea when you ask, and allowed() permits
lead:Pitched>Idea exactly while that comment is unanswered, so there's no third key to build.

The one thing to get right: your comment must carry no marker. comment lead/comment dev
append <!-- a-team:<role> -->, and unanswered() treats any <!-- a-team: marker as "not the
reviewer" — so a marked comment would be invisible as feedback and no run would ever be started by
it.

Needs #191 merged first: same reader, same hint bar, same command registrations.

Pitch: #180

Acceptance criteria

• a-team board <team> comment you <n> <file> posts the file as a comment on #<n>
  with no marker appended and no 👀 left on anything. check_role accepts you for
  comment (and keeps refusing unknown roles).
• c in the reader opens a comment dialog titled Comment on #<n>, with a TextView for
  the body, opened focused on it and empty.
• Ctrl+Enter posts it — not Enter, because the field is multi-line (style guide §5) — and
  TabKeyAddsTab is false so Tab still moves focus.
• Esc cancels and loses nothing else: you're back in the reader, still on the same pitch,
  scrolled where you were.
• After posting, the dialog closes, the reader stays open, and the MessageBar says
  commented on #<n>.
• An empty comment posts nothing and says so; it doesn't create a blank comment.
• The dialog's hint bar reads Ctrl+Enter post · Esc cancel, each a clickable Button per
  the style guide's Hint helper.
• The reader's hint bar carries all four:
  Up/Down/PgUp/PgDn scroll · a approve · c comment · o on GitHub · Esc close, with a absent
  on anything that isn't a Pitched pitch and c offered on any item.
• Registered: work.comment — "Comment on the item you're reading".
• A failed post keeps your text. The dialog stays open with what you wrote in it and the
  reason on the MessageBar in its Error colour — nothing you typed is thrown away.
• Work's own hint bar is unchanged.

Tests

• tests/scripts.sh: comment you posts a body containing no <!-- a-team: at all; it leaves no
  👀; feedback lead then reports that comment as the reviewer's unanswered feedback (the round trip
  that matters); an unknown role is still refused; --dry-run prints the body and posts nothing.
• tests/Dashboard.Tests: c opens the dialog with the item's number in its title and an empty
  TextView; Ctrl+Enter runs comment you with the typed body; Enter inside the field does not
  post; Esc cancels and posts nothing; an empty body posts nothing and shows a message; a failed
  post leaves the dialog open with the text intact; the reader's hint bar text with and without a;
  work.comment is registered with its label.

Out of scope

• A shelve key. Asking for it in a comment is the mechanism, and the Lead already has to honour
  it.
• Editing your own comment, or reading the thread. o covers both.
• Editing the pitch from the dashboard. You reply; the Lead revises.
• Markdown preview of what you're writing.
• Anything about telling your comments from the team's — I can't tell what the team said from what I said, and neither can GitHub #150.

[jamescrosswell]

Blocked by #191: #192 adds a third key to the same reader hint bar and the same command registrations #191 changes, so it lands after it.

[jamescrosswell]

Handing this back. My session's safety check refused the core change: letting a-team board comment you post with no marker and no 👀. It was flagged as weakening a safeguard, since it gives agents a way to post comments that read as your own feedback. No code was written. The unmarked post needs your sign-off, or you could build that step yourself. Either way, the agents' settings should also deny a-team board * comment you *, next to approve.

[jamescrosswell]

#191 is done so I don't think this is blocked. If it is blocked, what do you need from me to unblock?