plan synthetic and smart-flow phases

docs/implementation/synthetic-market-data/05-demo-load-profiles.md

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+# Synthetic Market-Data Phase 05: Demo and Load Profiles
+
+## Purpose
+
+Expose deterministic synthetic runs as named demo and load profiles after the generation, manifest, scenario, and replay foundations are in place.
+
+## Why this phase comes now
+
+Demos are useful only after the underlying data can be trusted. This phase deliberately waits until replay and golden evaluation prove the event semantics, so hosted controls do not become a front door to ambient randomness.
+
+## Dependencies on earlier phases
+
+- `islandflow-259.1` - Synthetic deterministic spine
+- `islandflow-259.2` - Manifests, fixtures, and CLI
+- `islandflow-259.3` - Scenarios, labels, and expected outputs
+- `islandflow-259.4` - Replay integration
+- `islandflow-zxh.4` - Smart-flow replay evaluation and golden tests
+
+## Likely files/modules touched
+
+- Thin synthetic emitters in `services/ingest-options/` and `services/ingest-equities/`
+- Demo/run selection API surfaces in `services/api/`
+- Web demo controls in `apps/web/`
+- Load profile definitions in the synthetic package
+- Tests for profile selection and rate scaling
+
+## In-scope work
+
+- Add named `DemoProfile` and `LoadProfile` definitions.
+- Make live/demo emitters thin consumers of deterministic synthetic runs.
+- Let demo controls select named runs/scenarios rather than changing hidden random behavior.
+- Ensure load profiles scale event rates without changing event semantics.
+- Document local demo usage once implemented.
+
+## Explicitly out-of-scope work
+
+- Foundation generator work.
+- New smart-flow scoring policy.
+- Replacing replay evaluation with UI-only checks.
+- Historical calibration.
+- Production provider configuration decisions.
+
+## Acceptance criteria
+
+- Demo profiles are deterministic and named.
+- Load profiles scale rate or volume without mutating scenario semantics.
+- Hosted or local controls select known runs/scenarios.
+- Live/demo emitters remain thin and do not own generator policy.
+- The UI does not expose synthetic controls before the backing deterministic runs exist.
+
+## Test strategy
+
+Use unit tests for profile parsing, profile selection, and rate-scaling semantics. Add replay-driven smoke checks for named demo runs. Manual UI validation is appropriate only after automated replay/golden checks pass.
+
+## Risks / design traps
+
+- Demo controls can pressure the codebase back into wall-clock randomness.
+- Load profiles may accidentally change business semantics while changing only rate was intended.
+- UI-first implementation can hide missing run provenance.
+- Reusing production config for synthetic demos can make operator behavior ambiguous.
+
+## Suggested future Codex implementation prompt
+
+```text
+Implement docs/implementation/synthetic-market-data/05-demo-load-profiles.md for Beads issue islandflow-259.5. Add named deterministic demo/load profiles and thin emitter/control integration only after replay validation exists. Do not implement historical calibration or change production provider policy.
+```
+
+## Matching Beads issue title/id
+
+- `islandflow-259.5` - Synthetic market-data phase 05: demo and load profiles