feat: architecture refactor — core layer, spreadsheet engine, envelope bidding, tests

- Add src/core/ (config, errors, events, http, observability, storage, query)
- Add src/Spreadsheet/ engine with native POI backend and Excel bridge
- Add Envelope C spreadsheet flow and tender bidding envelope modules
- Consolidate components into src/components/, remove legacy Component/ and Hooks/
- Add registration state/validation, auth session guard, profile edit modules
- Add unit tests across axios, redux, bidding, registration, encryption, core
- Add CI workflow, docs (architecture, audit, DSC API spec), keystore example
- Remove tracked keystore binary; ignore scripts.zip

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/Screens/Bidding/biddingPattern.ts

@@ -0,0 +1,78 @@
+/**
+ * Pattern configuration for the unified auction bidding screen/card.
+ *
+ * Forward and Reverse bidding were 90%-duplicated screens that drifted apart.
+ * Every behavioral difference between them is captured HERE, explicitly, so
+ * the screen and card contain zero `if (pattern === ...)` logic and a bidding
+ * fix can never again land in one pattern but not the other.
+ */
+import { FORWARD_AUCTION_ITEM, REVERSE_AUCTION_ITEM } from '../../Services/ApiCall/ApiUrls';
+
+export type AuctionPattern = 'Forward' | 'Reverse';
+
+export type BiddingFlags = {
+  oneTimeBid: boolean;
+  rebid: boolean;
+};
+
+export type BiddingPatternConfig = {
+  pattern: AuctionPattern;
+  /** Endpoint returning this pattern's auction items. */
+  itemsUrl: string;
+  /** Opening amount — the backend uses a different field per pattern. */
+  startValue: (item: any) => number;
+  /** Stepper step size. */
+  step: (item: any) => number;
+  stepLabel: 'Increment' | 'Decrement';
+  stepPrefix: '+' | '-';
+  /** Forward bids may rise without bound; reverse bids may not exceed the current bid. */
+  canIncrease: (bidValue: number, item: any) => boolean;
+  /** Forward bids may not drop below the current bid; reverse not below the EMD amount. */
+  canDecrease: (bidValue: number, item: any) => boolean;
+  /** Gate applied while typing a manual (one-time/rebid) amount. */
+  acceptManualInput: (value: number, item: any) => boolean;
+  /** Submit-time validation for manual bids; returns an error message or null. */
+  validateManualBid: (value: number, item: any) => string | null;
+  /** Reverse renders the manual input inline within the stepper row. */
+  inlineManualInput: boolean;
+  /** Whether the collapsible body opens at full height. */
+  isBodyFull: (flags: BiddingFlags, item: any) => boolean;
+  /** Whether the Confirm Bid button is rendered. */
+  showSubmit: (flags: BiddingFlags, item: any) => boolean;
+};
+
+const forward: BiddingPatternConfig = {
+  pattern: 'Forward',
+  itemsUrl: FORWARD_AUCTION_ITEM,
+  startValue: item => item?.auctionStartValueFigure,
+  step: item => item?.bidVariationValue,
+  stepLabel: 'Increment',
+  stepPrefix: '+',
+  canIncrease: () => true,
+  canDecrease: (bidValue, item) => bidValue > item.bidAmount,
+  acceptManualInput: () => true,
+  validateManualBid: (value, item) =>
+    value < Number(item.bidAmount) ? 'Enter a value greater than the current bid value' : null,
+  inlineManualInput: false,
+  isBodyFull: (flags, item) => !flags.rebid && item.contractorId == undefined,
+  showSubmit: (flags, item) => !flags.rebid && item.contractorId == undefined,
+};
+
+const reverse: BiddingPatternConfig = {
+  pattern: 'Reverse',
+  itemsUrl: REVERSE_AUCTION_ITEM,
+  startValue: item => item?.auctionStartValue,
+  step: item => item?.emdAmount,
+  stepLabel: 'Decrement',
+  stepPrefix: '-',
+  canIncrease: (bidValue, item) => bidValue < item.bidAmount,
+  canDecrease: (bidValue, item) => bidValue > item.emdAmount,
+  acceptManualInput: (value, item) => value >= 0 && value <= Number(item?.auctionStartValue),
+  validateManualBid: () => null,
+  inlineManualInput: true,
+  isBodyFull: () => true,
+  showSubmit: () => true,
+};
+
+export const getBiddingConfig = (pattern: string | undefined): BiddingPatternConfig =>
+  pattern === 'Reverse' ? reverse : forward;