0.2.27-0.2.32: LP portal polish, brand palette, default investor logins

Cumulative checkpoint since 0.2.26:
- 0.2.27/28: entity valuation-history table; investor gain/loss = NAV +
  distributions vs paid-in
- 0.2.29: Reset Fund Partners (endpoint, Partners-tab button, CLI, action)
- 0.2.30: "Current Capital Balance" label, %-only gain/loss
- 0.2.31: Management Entities rename, Carry Vehicle type, chart
  distributions-line gate
- 0.2.32: LP-facing polish pass
  * Ten31 brand palette from the logo (navy/mint); orange retired
  * portfolio summary card across funds; gain labeled "net of paid-in"
  * whole-dollar headline figures; "History · N quarters" toggle
  * documents grouped by year with a "New" badge (users.docs_seen_at)
  * eNAV-created members start on default password with login enabled;
    enable-investor-logins CLI + StartOS action for existing accounts
  * password minimum raised to 8 chars; login help line (Portal@ten31.xyz)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/ten31portal/models.py

@@ -39,6 +39,7 @@ class EntityType(str, enum.Enum):
     spv = "spv"
     gp = "gp"
     mgmt_co = "mgmt_co"
+    carry = "carry"
 
 
 class EntityStatus(str, enum.Enum):
@@ -75,6 +76,9 @@ class User(SQLModel, table=True):
     primary_account_id: int | None = Field(default=None, foreign_key="users.id", index=True)
     # Fund-administrator investor ID (from the eNAV ALLOC SI tab) for idempotent re-import.
     external_investor_id: str | None = Field(default=None, sa_column=Column(String, nullable=True))
+    # When this investor last loaded their documents list — docs newer than this get a "New"
+    # badge in the portal. Null until their first visit (nothing badged for brand-new logins).
+    docs_seen_at: datetime | None = Field(default=None)
     created_at: datetime = Field(default_factory=datetime.utcnow)