feat(stocks): add analyst consensus + price targets to stock analysis panel (#2926)

* feat(stocks): add analyst consensus + price targets to stock analysis panel

Shows recommendation trend (strongBuy/buy/hold/sell), price target range
(high/low/median vs current), and recent upgrade/downgrade actions with
firm names. Data from Yahoo Finance quoteSummary.

* chore: regenerate proto types and OpenAPI docs

* fix(stocks): fallback median to mean + use stock currency for price targets

* fix(stocks): drop fake $0 price targets and force refetch for pre-rollout snapshots

- Make PriceTarget high/low/mean/median/current optional in proto so partial
  Yahoo financialData payloads stop materializing as $0.00 cells in the panel.
- fetchYahooAnalystData now passes undefined (via optionalPositive) when a
  field is missing or non-positive, instead of coercing to 0.
- StockAnalysisPanel.renderPriceTarget skips Low/High cells entirely when the
  upstream value is missing and falls back to a Median + Analysts view.
- Add field-presence freshness check in stock-analysis-history: snapshots
  written before the analyst-revisions rollout (no analystConsensus and no
  priceTarget) are now classified as stale even when their generatedAt is
  inside the freshness window, so the data loader forces a live refetch.
- Tests cover undefined targets path, missing financialData path, and the
  three field-presence freshness branches.

* fix(stocks): preserve fresh snapshots on partial refetch + accept median-only targets

- loadStockAnalysis now merges still-fresh cached symbols with refetched
  live results so a partial refetch does not shrink the rendered watchlist
- renderAnalystConsensus accepts median-only price targets (not just mean)

docs/api/MarketService.openapi.yaml

@@ -1224,6 +1224,14 @@ components:
                     format: double
                 engineVersion:
                     type: string
+                analystConsensus:
+                    $ref: '#/components/schemas/AnalystConsensus'
+                priceTarget:
+                    $ref: '#/components/schemas/PriceTarget'
+                recentUpgrades:
+                    type: array
+                    items:
+                        $ref: '#/components/schemas/UpgradeDowngrade'
         StockAnalysisHeadline:
             type: object
             properties:
@@ -1237,6 +1245,65 @@ components:
                     type: integer
                     format: int64
                     description: 'Warning: Values > 2^53 may lose precision in JavaScript'
+        AnalystConsensus:
+            type: object
+            properties:
+                strongBuy:
+                    type: integer
+                    format: int32
+                buy:
+                    type: integer
+                    format: int32
+                hold:
+                    type: integer
+                    format: int32
+                sell:
+                    type: integer
+                    format: int32
+                strongSell:
+                    type: integer
+                    format: int32
+                total:
+                    type: integer
+                    format: int32
+                period:
+                    type: string
+        PriceTarget:
+            type: object
+            properties:
+                high:
+                    type: number
+                    format: double
+                low:
+                    type: number
+                    format: double
+                mean:
+                    type: number
+                    format: double
+                median:
+                    type: number
+                    format: double
+                current:
+                    type: number
+                    format: double
+                numberOfAnalysts:
+                    type: integer
+                    format: int32
+        UpgradeDowngrade:
+            type: object
+            properties:
+                firm:
+                    type: string
+                toGrade:
+                    type: string
+                fromGrade:
+                    type: string
+                action:
+                    type: string
+                epochGradeDate:
+                    type: integer
+                    format: int64
+                    description: 'Warning: Values > 2^53 may lose precision in JavaScript'
         GetStockAnalysisHistoryRequest:
             type: object
             properties: