docs(P03): complete freeholders docs + reference phase — REQ-027 complete

P3 complete. 8 docs/freeholders/ pages (signals, standing, stands-guilds,
councils-voice, bonds, partner-spectrum, anchor-preview, index) + 2
docs/reference/ pages (architecture, components). Docs firewall green
across all 26 docs pages. Full docs deliverable (README + mkdocs.yml +
26-page site) complete — REQ-027 complete.

---ci---
project: oy
phase: 3
milestone: v0.3
status: complete
tag_base: v0.2.x
phase_role: execution
requirements:
  covered: [REQ-027]
  partial: []
---/ci---

docs/freeholders/anchor-preview.md

@@ -0,0 +1,47 @@
+# Anchor Preview
+
+An **Anchor** (REQ-023) is the fourth and highest tier of the
+[Partner Spectrum](partner-spectrum.md) (REQ-018) — the first **institutional**
+Partner tier. Anchors are coming in v0.3 P4. This page previews what an Anchor
+is and what the v0.3 skeleton will deliver; the runtime behavior is deferred
+to v0.4+.
+
+## What an Anchor is
+
+An Anchor is a Partner that carries an **AnchorCredential**: a jurisdiction
+(e.g., "EU-MiCA"), a custody provider, and a set of attestation references.
+The Anchor tier is how the jurisdiction-light mesh interfaces with
+jurisdiction-bound institutional actors without becoming them. An Anchor
+holds a credential; the [Holder](../nomads/reach.md) still holds their
+[Stash](../nomads/stash.md). The mesh says **custody**, **compliance**, and
+**jurisdiction** — never the legacy institutional words banned by the
+[lexicon](../shared/lexicon.md).
+
+## What is coming in v0.3 P4
+
+v0.3 P4 (REQ-023) extends `x/partner` with the `AnchorCredential` struct and
+a `Partner.AnchorCredential()` accessor (returns nil for non-Anchor tiers).
+The four-tier `PartnerTier` enum (Op, Master Op, Pier, Anchor) is **unchanged**
+— v0.3 adds Anchor-specific fields, not a new tier. The custody-provider-id
+field is a by-ID-string reference to `x/hub` (the Hub API, coming in v0.3 P5),
+empty in the v0.3 skeleton because the Hub is not live until P5/v0.4. This is
+the P4→P5 ordering edge: `x/hub` in P5 references Anchor partner-ids from P4.
+
+## Why Anchors matter to a Freeholder
+
+A Freeholder engaging an Anchor gets a Partner with a verifiable credential
+and a custody/compliance relationship — useful for cross-jurisdiction routes
+and institutional [bonds](bonds.md). The Anchor's [Standing](standing.md) and
+attestations are visible so the Freeholder can verify the Anchor is real
+before opening a [Window](../nomads/window.md). See
+[Partner Spectrum](partner-spectrum.md) for the other three tiers, and
+[Councils & Voice](councils-voice.md) for how the Mesh Council can suspend or
+revoke an Anchor.
+
+## What v0.3 does not deliver
+
+The v0.3 skeleton is types + tests only (D-035): the `AnchorCredential`
+struct, the accessor, and the `ListAnchors()` keeper alias. Live custody
+routing, attestation verification, and the Hub API integration are v0.4+
+runtime work. See [Components](../reference/components.md) for the full
+module map.