feat(draft): replace Cogwork Librarian opt-out dialog with opt-in button

[billyhewlett]

Problem

When a player holds Cogwork Librarian during a cube draft, the current
implementation prompts "Draft an extra pick with Cogwork Librarian?" (Yes/No)
on every single pick until the player chooses to use it. The player must
actively click "No" on each pack they want to draft normally, which is
disruptive when they are waiting for the right pack to use the ability.

Additionally, there is a pre-existing bug: if a player activates Cogwork
and then drafts a card that has a draft action (e.g., Lore Seeker), the
extra pick is silently dropped. draftCard() ends with a hardcoded
return true when any draft action runs, overriding the passPack = false
set by Cogwork's handler.

Changes

LimitedPlayer.java

• Add cogworkLibrarianActivatedByUI public flag, consumed by
  handleCogworkLibrarian() instead of showing a dialog. Defaults to
  false, so the ability is not used unless the player explicitly opts in.
• Add hasCogworkLibrarianAvailable() predicate so the UI can query
  pending state without touching internal flags.
• Replace handleCogworkLibrarian() dialog prompt with flag-read-and-clear.
• Fix draftCard() to return passPack instead of hardcoded return true,
  so Cogwork combined with draft-action cards (Lore Seeker, etc.) works
  correctly.

FDeckEditor.java (mobile)

• Add a persistent btnUseLibrarian button in DraftPackPage, hidden by
  default. Appears above the card list when Cogwork is pending.
• Override doLayout() to reserve space for the button when visible.
• Button tap sets cogworkLibrarianActivatedByUI = true and hides itself.
• Button is hidden at start of moveCard() and re-evaluated in refresh()
  after each pack loads.

Behavior Change

Before	After
Dialog on every pick while holding Cogwork; must click "No" to skip	Button visible while Cogwork is pending; tap once to use it
Extra pick dropped when combined with draft-action cards	Extra pick correctly retained

Testing

Draft with a cube containing Cogwork Librarian. Verify:

1. Button appears when Cogwork is in hand.
2. Tapping it grants the extra pick for that pick only.
3. Not tapping it skips the pick silently — no dialog.
4. Drafting Lore Seeker while Cogwork is pending correctly grants both effects.