Release 0.2.22: capital chart, Investor View, GP stakes, doc folders

Snapshot commit bringing the uncommitted phase-2 work into version control
together with four new features and the 0.2.22 version bump.

New features:
- Investor capital-over-time chart (value, paid-in, distributions per
  quarter), rendered from existing capital-account history.
- Admin Investor View: read-only reconstruction of an investor's portal
  (GET /api/users/{id}/investor-view), reusing the investor portal UI.
- Document upload scoped to the selected fund's own investors, with an
  explicit upload-target confirmation to prevent mis-attaching.
- GP/mgmt entities gain an Assets tab listing their stakes in the funds
  they manage (new entity_stakes table + /api/entities/{id}/stakes).
- Edit-entity form (change type/status/etc.), so GP entities can be
  categorized correctly.

Verified: 11/11 backend tests pass; alembic upgrades to head b8c9d0e1f2a3;
frontend tsc + vite build clean; s9pk packs at 0.2.22:0 (x86_64).
Also: ignore .DS_Store and *.s9pk artifacts.

backend/ten31portal/models.py

@@ -207,3 +207,23 @@ class CapitalAccountStatement(SQLModel, table=True):
     ending_balance_cents: int = 0      # current capital value
     document_id: int | None = Field(default=None, foreign_key="documents.id", index=True)
     created_at: datetime = Field(default_factory=datetime.utcnow)
+
+
+class EntityStake(SQLModel, table=True):
+    """A holder entity's ownership stake in a fund/SPV it manages.
+
+    Models the assets of a GP or management company: its interest in each fund it manages,
+    which are entities in their own right rather than portfolio-company holdings.
+    """
+    __tablename__ = "entity_stakes"
+    __table_args__ = (
+        UniqueConstraint("holder_entity_id", "fund_entity_id", name="uq_stake_holder_fund"),
+    )
+
+    id: int | None = Field(default=None, primary_key=True)
+    holder_entity_id: int = Field(foreign_key="entities.id", index=True)  # the GP / mgmt co
+    fund_entity_id: int = Field(foreign_key="entities.id", index=True)    # the fund/SPV held
+    ownership_pct: float | None = None   # e.g. 20.0 for a 20% interest
+    value_cents: int | None = None       # optional current value of the stake
+    note: str | None = None
+    created_at: datetime = Field(default_factory=datetime.utcnow)