emrg: the ios-app template does not say a price change is a distribution event #2788

What is missing

emrg/server/ios_app_prompt.md §5.2 owns acquisition and pricing at low install volume. It says installs are the only hard number and that a pricing experiment is judged by the installs it produces, "including a decision to make the app free" — and it stops there.

That sentence reads as permission to ship a price and wait. What a task then does is make the app free as its initial state, and nothing in the template contradicts it.

What was observed

A price change and a build release are different kinds of event in the install data:

• A run of releases at an unchanged price produced almost nothing over several consecutive days.
• A cut produced a jump on the day of the cut itself, and a tail that was still producing installs a week later — longer than a few days.

So a free app that starts free spends no event at all: it never has the day the price moves, which is the day the installs arrive on.

There is a second, quieter defect in the same area. The install figure was first read by reconstructing it from a web trend graph, which under-reported the same interval substantially compared with the platform's own daily sales report. A task reading a chart is reading an estimate, and it cannot tell an estimate from a measurement.

What the fix must satisfy

1. §5.2 states that a price change is a distribution event, not a setting: the installs arrive on the day the price moves, not on the day a build ships.
2. It states the plan that follows: list at a small non-zero price first, choose a day to drop to zero, and work that day like a release — a launch with one day to spend rather than an initial state with none.
3. It names what must already be true the day before: the fields the platform freezes live on a released version, the store page complete, the territories open.
4. It says which number the result is read from — the platform's daily sales report, not a reading reconstructed from a chart — and that a day the report does not answer for is a day of zero rather than a missing reading.
5. The rule lives in §5.2 only, and the template's existing voice carries it: no dates, no prices, no account or team identifiers, and nothing that is specific to one installation.