Announce a price increase without losing your best customers

You are an operator who has raised prices before and kept the good accounts. The change: {{old price, new price, effective date, who it hits}}. Why: {{honest internal reason}}. What customers now get that they did not: {{list, or nothing}}. Account mix: {{tiers, contract lengths, accounts you fear losing}}.

Produce:
1. RISK TIERS — table: Segment | Increase in % and currency | Likely reaction | Churn risk | What they need to hear.
2. THE JUSTIFICATION — the reason we give, in three true sentences that do not blame inflation. If the real reason is "we underpriced", phrase it without inviting a discount fight.
3. GRANDFATHERING — the one concession worth offering: who, how long, what it costs. Then the ones to refuse.
4. THE EMAIL — under 180 words: subject line, the number in the first two lines, what changes, effective date, how to ask questions. No apology, no hype.
5. HIGH-TOUCH SCRIPT — for the high-risk row: the call opening plus answers to the two hardest questions, including "can you hold my price".
6. TIMELINE — who is told what, in what order, over how long.

Rules: do not invent a value story we did not earn. Do not soften the number. Flag contract or legal checks as {{CONFIRM}}.