feat(filltracker,engine,ws,storage)!: track fills and size TP from executed position; replace naive TP cancel

WHY:
Replicating a bot without tracking actual fills can over-order (planned ladder ≠ executed fills). The bot is unaware of our replication, so TP sized from the plan becomes wrong after any fill. We must trade the executed position, not the plan, and keep TP reduce-only to current net size.

Introduce filltracker.Service to aggregate executed/outstanding orders per deal and expose snapshots:

• Rebuild(ctx) to hydrate from storage
• UpdateStatus(md, wsOrder) to ingest HL updates
• Snapshot(dealID) to read net qty/avg entry/active TP/open buys
• CancelCompletedTakeProfits(ctx, submitter) to drop stale TP when all buys filled

Engine:

• WithFillTracker; processDeal consults snapshot
• adjustActionWithTracker: TP qty == net position, reduce_only=true; skip when flat
• Idempotent: only change when different from exchange state

Main:

• Wire tracker into ws and engine
• Replace cancelTakeProfit with reconcileTakeProfits using tracker

WS:

• New(ctx, store, tracker, wallet, url); forward order updates into tracker before persisting

Storage:

• New(path, ...opts) with storage.WithLogger
• ListMetadataForDeal(ctx, dealID) to support tracker rebuild

Tests:

• filltracker/service_test.go and engine tests cover TP sizing and partial fills

BREAKING CHANGE:

• storage.New(path, logger) → storage.New(path, storage.WithLogger(logger))
• ws.New(ctx, store, wallet, url) → ws.New(ctx, store, tracker, wallet, url)
• TP placement now always derived from executed position and marked reduce_only