15.x.x-alpha.1: Minimize API Surface

[varrockbank]

Change	Migration
Remove automatic tab expansion	Use BuffeeSanitize extension or sanitize text before passing to Model._ or Span.ins()
Span.ins() takes array of lines	Span.ins('text') → Span.ins(['text'])Span.ins('line1\nline2') → Span.ins(['line1', 'line2'])
buffee-clip textarea removed	Remove <textarea class="buffee-clip"> from HTML template
Model.s = "text" removed	Use Model._ = ["text"]; View.render();

New APIs

API	Description
Model.end	Returns last coordinate {y, x} in document
Span.select(pos)	Accepts optional position to set head when starting selection
Mode.mx	Max column for vertical cursor movement (was internal maxCol)
Mode.ext	Array of registered extension names in order
BuffeeSanitize extension	Opt-in text sanitization (tabs→spaces, zero-width removal)

Renamed APIs

Old	New
View.set(x)	View.first = x (setter)
View.set(x, n)	View.first = x, View.n = x (setter)
View.size()	View.n (getter/setter)
View.start	View.first
View.end	View.last
render()	View.render()
RENDER()	View.RENDER()
Config cols	Config w
Config rows	Config h

Removed APIs

API	Reason
View._ getter	Unused, reduces API surface
Model.s setter	Delegate Model._ update and rendering to user