View a policy version's content, and make policy text readable

The Policies admin page listed versions but never showed what any of them
said, so revising a policy meant retyping it blind into an empty draft box.
Each version row now has a View action that renders that version's text on
the page, editable in place. A draft is saved back to itself; editing a
published or archived version branches a new draft and leaves the original
alone, because acceptances are recorded against policy_version_id and text a
student agreed to must stay exactly as they saw it.

That viewer also exposed why a studio reported the acceptance box as
unreadable — one squashed line, overlapping words, a horizontal scrollbar.
Bodies are typed into a bare textarea, so most carry no markup, and the raw
text was emitted with its blank lines intact but nothing to turn them into
paragraphs. PolicyVersion::bodyHtml() now renders every body the way
WordPress renders post content (kses, then wpautop) and feeds all three
consumers: the booking/enrolment JSON, the signup form, and the new viewer.
Bodies written with markup are unaffected.

The other half was that .us-policy-body had no CSS whatsoever and inherited
whatever the theme did with an unstyled block in a form. It is now a bounded
reading box that scrolls vertically and breaks long tokens, so a pasted URL
cannot force the page sideways and a long policy cannot push the accept
checkbox out of view. RegistrationPage was also never enqueueing the plugin
stylesheet, which is why the signup gate looked worst of all.

Closes #126
Closes #127

Co-Authored-By: Claude Opus 5 <[email protected]>

CHANGELOG.md

@@ -18,8 +18,12 @@ each change under the current top section as you work.
 
 ### Added
 - Every price a student sees now says **when** it is due. Lesson types in the booking form read `50.00 CAD at booking`, and group-class cards read `120.00 CAD up front`, `40.00 CAD weekly` or `40.00 CAD monthly` — the offering's billing mode, in the student's words. A monthly **private lesson** is quoted per lesson (`50.00 CAD per lesson monthly`), since its monthly charge covers every lesson booked that month; a monthly group class is quoted as the monthly figure it is. A free offering still just reads **Free**.
+- The **Policies** admin page can now **show you what is actually in a version**. Every row in the versions table has a **View** button that opens that version's text below the table, rendered exactly as students see it at booking and signup, whether the version is the published one, an old archived one, or a draft nobody has seen yet. The text is editable straight from the viewer, and what happens when you save depends on the version: a draft is simply updated in place, while editing a **published or archived version saves your text as a new draft version** and leaves the original exactly as students accepted it. The new draft then opens in the viewer ready to publish. Nothing a student has agreed to is ever rewritten.
 - Booking a lesson and enrolling in a class now take a **second confirmation that the student agrees to pay**. Above the Confirm button the form restates the price with its cadence, spells out how it is collected ("Charged on the 1st of each month, for that month's lessons"), adds the studio's HST so the figure matches the total actually billed, and requires a tick on "I agree to pay 56.50 CAD at booking." before it will submit — separate from, and in addition to, the studio policies the student accepts above it. Reserving a time weekly quotes the per-lesson fee and the most it can add up to ("up to 12 lessons, 678.00 CAD in total"), since a week another student takes first is simply not booked. Free offerings have nothing to agree to and show no price block.
 
+### Fixed
+- Policies are **readable where students have to accept them**. A policy typed as plain paragraphs — the normal way to write one, with no HTML — was being dropped into the booking, enrolment, and signup forms unformatted, collapsing the whole document into a single squashed line with a horizontal scrollbar and words piling on top of each other. Policy text is now formatted the same way WordPress formats post content, so blank lines become real paragraphs, and the acceptance box is styled as a proper bounded reading panel: long policies scroll vertically instead of running off the side of the page, long pasted links wrap rather than forcing the page sideways, and the "I have read and agree" tick stays in view. Policies written with HTML are unaffected. The studio registration page was also missing the plugin's stylesheet entirely, which is why the problem was at its worst there.
+
 ## [1.2.2]
 
 ### Added