Add Insiders tab with diverging bar chart and transaction table

- Backend: get_insider_transactions() in data_service (yfinance, 1hr TTL)
- Backend: InsidersResponse schema + GET /api/tickers/{symbol}/insiders
- Frontend: InsidersPage with 4-KPI strip, SVG diverging bar chart (),
  psm-insider transaction rows, pill filter toggles, shimmer skeleton,
  empty/error states
- Enable Insiders nav item (remove disabled flag)

1 files changed, 28 insertions, 0 deletions

diff --git a/backend/app/schemas.py b/backend/app/schemas.py
index c84b4c6..b1d934a 100644
--- a/backend/app/schemas.py
+++ b/backend/app/schemas.py
@@ -206,5 +206,33 @@ class RatiosResponse(BaseModel):
     dividend_payout: RatioPoint
 
 
+class InsiderTransaction(BaseModel):
+    date: str | None = None
+    insider: str
+    position: str
+    direction: Literal["buy", "sell", "other"]
+    shares: int | None = None
+    value: float | None = None
+
+
+class InsiderMonthPoint(BaseModel):
+    month: str
+    buy: float
+    sell: float
+
+
+class InsiderSummary(BaseModel):
+    buy_count: int
+    sell_count: int
+    buy_value: float
+    sell_value: float
+
+
+class InsidersResponse(BaseModel):
+    summary: InsiderSummary
+    monthly_chart: list[InsiderMonthPoint] = Field(default_factory=list)
+    transactions: list[InsiderTransaction] = Field(default_factory=list)
+
+
 class ErrorResponse(BaseModel):
     detail: str