Updates MULTI_VENUE_BUGS.md to reflect:
- Resolved: SQL duplicate clauses (commit cd763cf)
- Clarified: OrderId is not redundant (tracks 3commas orders)
- Renumbered remaining bugs #1-8 (from #1-12)

Remaining critical issues:
- Bug #1: OrderWork comparability violation
- Bugs #2-6: Scaled orders multi-venue architecture

…rable

The Action struct had pointer fields (Create, Modify, Cancel) which made
it non-comparable in Go. Since OrderWork embeds Action and the typed queue
requires comparable structs, this violated Go's comparability requirements.

The fix removes the pointers and uses value types instead. The ActionType
field already indicates which action is active, making nil checks redundant.

This change:
- Changes Action fields from pointers to values
- Updates all action creation sites to use values instead of pointers
- Removes all nil pointer checks, replacing them with ActionType checks
- Updates all dereferences to use values directly
- Updates test assertions to remove NotNil checks

Resolves Bug #1: OrderWork Comparability Violation as described in
specs/multi_venue_emission.adoc

Updates MULTI_VENUE_BUGS.md to reflect:
- Resolved: SQL duplicate clauses (commit cd763cf)
- Clarified: OrderId is not redundant (tracks 3commas orders)
- Renumbered remaining bugs #1-8 (from #1-12)

Remaining critical issues:
- Bug #1: OrderWork comparability violation
- Bugs #2-6: Scaled orders multi-venue architecture

Updated MULTI_VENUE_BUGS.md to reflect resolved issues:

Resolved (PRs #75 and #76):
- Bug #1: OrderWork comparability violation
- Bug #2-4: Scaled orders multi-venue architecture

Remaining issues (renumbered #1-4):
- Bug #1: Missing scaled_orders in wallet migration (High)
- Bug #2: Take profit reconciliation fan-out (Medium)
- Bug #3: Fill tracker memory growth (Medium)
- Bug #4: Replay logic edge case (Low)

PRs:
- #75: Removed pointer fields from Action struct
- #76: Fixed multi-venue scaled order handling

Add scaled_orders table migration to migrateDefaultVenueWalletLocked:
- Clone scaled_orders from old wallet to new wallet
- Delete scaled_orders associated with old wallet

This ensures the scaled order audit trail is preserved when a user
changes their Hyperliquid wallet address, matching the behavior of
hyperliquid_submissions and hyperliquid_status_history tables.

Fixes Bug #1: Missing scaled_orders in Wallet Migration

Critical fixes for multi-venue take-profit reconciliation:

Issue #1 (P1): Each venue's take-profit was being sized to the GLOBAL net
position instead of that specific venue's position. This caused oversized
exit orders (e.g., if venue A had 60 and venue B had 40, both would try
to exit 100, totaling 200 and overshooting inventory).

Fix: Added calculateVenuePositions() to compute net position per venue
by summing filled buy/sell quantities for each venue identifier. Each
venue's take-profit is now correctly sized to match only its position.

Issue #2 (P1): ensureTakeProfit was only called when NO active take-profits
existed. If one venue had an active TP, other venues without TPs would
never get them created, leaving the multi-venue fan-out incomplete.

Fix: Changed logic to iterate through ALL venue positions and reconcile
or create take-profits for each venue independently. Now checks per-venue:
- If venue has position but no TP: create one
- If venue has position and TP: reconcile size
- If venue has no position but TP exists: cancel it

Location: filltracker/service.go:155-215