Remove a file related to import optimization plan.

docs/import_optimization_plan.md

@@ -1,36 +0,0 @@
-# Import Optimisation Plan
-
-## Goals
-- Prevent large imports from exhausting memory or hitting IO limits while reading export archives.
-- Maintain correctness and ordering guarantees for all imported entities.
-- Preserve observability and operability (clear errors and actionable logs).
-
-## Current Status
-- ✅ Replaced `File.read + JSON.parse` with streaming via `Oj::Parser(:saj).load`, so `data.json` is consumed in 16KB chunks instead of loading the whole file.
-- ✅ `Users::ImportData` now dispatches streamed payloads section-by-section, buffering `places` in-memory batches and spilling `visits`/`points` to NDJSON for replay after dependencies are ready.
-- ✅ Points, places, and visits importers support incremental ingestion with a fixed batch size of 1,000 records and detailed progress logs.
-- ✅ Added targeted specs for the SAJ handler and streaming flow; addressed IO retry messaging.
-- ⚙️ Pending: archive-size guardrails, broader telemetry, and production rollout validation.
-
-## Remaining Pain Points
-- No preflight check yet for extreme `data.json` sizes or malformed streams.
-- Logging only (no metrics/dashboards) for monitoring batch throughput and failures.
-
-## Next Steps
-1. **Rollout & Hardening**
-   - Add size/structure validation before streaming (fail fast with actionable error).
-   - Extend log coverage (import durations, batch counts) and document operator playbook.
-   - Capture memory/runtime snapshots during large staged imports.
-2. **Post-Rollout Validation**
-   - Re-run the previously failing Sidekiq job (import 105) under the new pipeline.
-   - Monitor Sidekiq memory and throughput; tune batch size if needed.
-   - Gather feedback and decide on export format split or further streaming tweaks.
-
-## Validation Strategy
-- Automated: streaming parser specs, importer batch tests, service integration spec (already in place; expand as new safeguards land).
-- Manual: stage large imports, inspect Sidekiq logs/metrics once added, confirm notifications, stats, and files restored.
-
-## Open Questions
-- What thresholds should trigger preflight failures or warnings (file size, record counts)?
-- Do we need structured metrics beyond logs for long-running imports?
-- Should we pursue export format splitting or incremental resume once streaming rollout is stable?