ppsds 0.0.3-alpha (0.0.3a0)

A public alpha pre-release, on PyPI as 0.0.3a0. Install it with
pip install ppsds==0.0.3a0 (or pip install --pre ppsds); the GitHub Release is marked
pre-release. This is the first release published to PyPI, so the docs site and the repository
become public with it.

Added

• The game page's first-visit tour — a six-step card pinned to the table's lower-left corner
  over the first round, with a bouncing arrow pointing at the one thing each step is about. It
  waits for its own action — turn on prediction, place a stack, cover the noise support, change a
  height, deal, next round — and Next stays disabled until the table is in that state;
  Back re-reads the previous step without undoing anything. Skip closes the tour for the
  visit and also keeps the static "Place your stacks" hint out of the way; the last step closes the
  card as soon as Next round is pressed. A teaching switch beside Hide panel turns it off, the
  guide restarts it, and nothing is stored: every visit starts it again.
• Batch selection — a Select mode plus Shift-click and a box gesture; the height slider,
  −/+, Remove and dragging all act on the selection, and a group move is refused whole if any
  destination is taken.
• Noise-support overlay — the landing law is drawn around the prediction in the marker's gold
  at a low opacity: the exact box for uniform noise, the weighted bands of a block law, a 3σ window
  for a Gaussian, and nothing on a table that keeps its law. It is part of the prediction switch,
  not a switch of its own.
• Auto-continue — advance a settled round after a pause, separately from auto-play.

Changed

• The game's starting points — each table's x0 is chosen so the one-step nominal displacement
  is at least the noise's RMS radius. The drift matrices and noise laws are unchanged, so par and
  the safe layouts do not move; the replay states are re-recorded.
• The height control — a reachable cap at eight times a fresh stack, a gentler −/+ step
  (12%) and a slower hold-to-repeat, so a tower cannot be made unreadable by a mis-touch.
• keep my layout starts on, and the Deal / Next round / Play again button carries a phase
  icon and a settled-state highlight.
• The table starts bare — prediction and last rounds start off, so the first thing on the
  felt is the puck alone; the tour's first step turns the prediction (and, with it, the gold noise
  support) on. Neither switch changes a number.

Removed

• Undo, long-press deletion and the Move button. Clear and a batch Remove ask for a second
  press, since there is no longer an undo to recover them.

Fixed

• A tap on bare felt while a stack's toolbar is open now only closes the toolbar instead of also
  placing a stack under the hand.
• The game page's direct link in the docs now includes the examples/ path segment.