Waterline v1 projection import has no event or history byte limit #770

Published Server 2.11.1's Waterline v1 projection import has no limit on how much history one import writes.

Behavior. POST /api/workflows/import/waterline-v1 (LegacyV1ProjectionController, LegacyV1Projection::normalize) turns every logs, signals and exceptions row into one projected history event. It sorts them, then writes each event with its own INSERT in a single transaction. Nothing bounds the row count, the event count or the projected history bytes. Within the 2 MiB request cap, one admin request can carry hundreds of thousands of tiny rows. That one request then causes a large memory, database-lock and write burst.

Expected. An explicit, public hard limit on projected events and on total projected history bytes. It should be checked before any existing row is read and before the write transaction, with zero rows written on refusal.

Native. Server #768 (Rust #325) reuses the completion-budget limits from Workflow #930 (DW_V2_LIMIT_HISTORY_TRANSACTION_SIZE, default 5,000 events; DW_V2_LIMIT_HISTORY_TRANSACTION_BYTES, default 16 MiB), since one projection import is one transaction writing that history.

• A source is refused from a cheap row count before it is copied, then by its exact event count and history bytes after normalization. Both checks come before any read or write.
• The refusal is a 409 report with reason: v1_projection_too_large and limit: {dimension, used, limit}.

Please confirm or change these names and defaults for PHP, so both servers enforce the same contract.

Found by Security's review of #768. Handed to the General owner for the PHP contract and fix.