There was no way to say "tell me when ES reaches 7800". The only user-settable
alert was a drawn trendline, placed by clicking two points on a canvas — so you
could not hit an exact price, and making the line flat was fiddly.
A price alert is a manual line with zero slope. Reusing that rather than
building a parallel concept means it inherits JSON persistence, renaming,
recolouring, deletion, clustering, and the rule that a hand-placed level alerts
whatever its confluence score. The only genuinely new code is the input, an
endpoint that takes a price instead of two anchors, and the decision to render
zero-slope manual lines as price lines — which spans the chart and labels the
axis, instead of drawing a stubby two-point segment.
Zero-slope lines also skip drag handles, hit-testing and the "end line here"
menu: a price line has no endpoints to grab. They are managed from the sidebar.
Unlabelled alerts are named by their price, since "1d resistance" does not say
which alert fired.
Verified live: a level typed 25 points above price clusters as resistance at
that price and stays quiet, as it should until price arrives.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
