docs+smoke(v7): visibility section in virtual-llms.md + register/list smoke

Wraps up v7 Stage 3:

- docs/virtual-llms.md gains a "Visibility scope (v7)" section that
  explains public-vs-private semantics, who skips the filter (owner +
  `*` admin), how to grant single-row exceptions via name-scoped RBAC,
  per-row override syntax in mcplocal config, the `--visibility` flag
  on `mcpctl create llm`/`create agent`, and YAML round-trip behavior.
- New smoke (virtual-llm-visibility.smoke.test.ts) publishes one
  public + one private virtual Llm via the registrar against the
  live mcpd and asserts the GET /llms response carries visibility
  + a non-empty ownerId for both, and that GET /llms/<name> returns
  the private row to its owner without 404. Cross-user filtering is
  covered by mcpd's visibility-filter unit tests; smoke proves the
  fields make the round-trip end-to-end.

Will pass once mcpd is rebuilt + deployed via fulldeploy.sh on this
branch (current main is v6, doesn't yet serialize visibility).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/virtual-llms.md

@@ -431,10 +431,100 @@ mid-task reverts the row to pending instead of failing the caller.
 See [inference-tasks.md](./inference-tasks.md) for the full data
 model, async API, lifecycle, RBAC, and CLI surface.
 
+## Visibility scope (v7)
+
+Virtual Llms and Agents now carry an explicit **visibility** field that
+decides who can see the row in listings.
+
+| Visibility  | Meaning                                                                          |
+|-------------|----------------------------------------------------------------------------------|
+| `public`    | Visible to anyone with `view:llms` / `view:agents`. Default for hand-created Llms. |
+| `private`   | Only the **owner** plus principals with a name-scoped grant can see it. Default for virtual Llms and Agents on first publish. |
+
+The owner is whichever user authenticated the publishing
+`POST /api/v1/llms/_provider-register` (or `mcpctl create llm`). For
+mcplocal that's whichever `~/.mcpctl/credentials` token is on disk.
+Legacy rows from before v7 default to `visibility=public, ownerId=NULL`,
+so the upgrade is a no-op for everything that already exists.
+
+### Who skips the filter?
+
+Two principals see every row regardless of visibility:
+
+1. The **row owner** (`ownerId === request.userId`).
+2. Anyone with a **cross-resource admin** grant — RBAC binding
+   `{ resource: '*' }`. Operationally this is the SRE / cluster admin.
+
+A plain `view:llms` resource grant is *not* the same as admin: it's a
+RBAC wildcard for name-scoping (you can name any Llm), but the
+visibility filter still applies on top. This is the v7 split that
+prevents a user with `view:llms` from enumerating every developer's
+private virtual Llm.
+
+### Granting a single-row exception
+
+When alice wants bob to see her private virtual Llm `alice-vllm-local`
+without making it public, she binds:
+
+```sh
+mcpctl create rbac bob view:llms --name alice-vllm-local
+```
+
+Same shape as any other name-scoped binding. Removing the binding
+flips bob back to "row not found".
+
+### Publishing as private from mcplocal
+
+mcplocal defaults to `private` for every published provider and agent.
+Override per-row in `~/.mcpctl/config.json`:
+
+```jsonc
+{
+  "llm": {
+    "providers": [
+      { "name": "vllm-local",  "type": "vllm", "model": "...", "publish": true,
+        "visibility": "private" },                                 // default; explicit for clarity
+      { "name": "shared-qwen", "type": "vllm", "model": "...", "publish": true,
+        "visibility": "public" }                                   // every team member can chat with it
+    ]
+  },
+  "agents": [
+    { "name": "local-coder", "llm": "vllm-local",
+      "visibility": "private" }                                    // private agents pinned to private Llms
+  ]
+}
+```
+
+On a sticky reconnect (`providerSessionId` matches an existing row)
+the visibility is **only** updated when the publisher explicitly sends
+it — leaving the field off keeps whatever the row already has,
+including any field admin set out-of-band.
+
+### Hand-created Llms
+
+`mcpctl create llm` defaults to `public` (matches pre-v7 behavior).
+Pass `--visibility private` to opt in:
+
+```sh
+mcpctl create llm my-key --type openai --model gpt-4o \
+  --api-key-ref my-secret/key --visibility private
+```
+
+The same `--visibility` flag is on `mcpctl create agent`.
+
+### CLI surface
+
+`mcpctl get llm` and `mcpctl get agent` show a `VISIBILITY` column.
+YAML round-trips cleanly: `mcpctl get llm X -o yaml | mcpctl apply -f -`
+preserves visibility, and `ownerId` is stripped from the apply doc
+because it's server-side state (the apply re-stamps the ownerId of the
+authenticated caller, not the original creator).
+
 ## Roadmap (later stages)
 
-(LB pool by name landed in v4; durable task queue landed in v5.)
-- **v6** — multi-instance mcpd via pg `LISTEN/NOTIFY` (replaces the
+(LB pool by name landed in v4; durable task queue landed in v5;
+visibility scope landed in v7.)
+- **v8** — multi-instance mcpd via pg `LISTEN/NOTIFY` (replaces the
   per-instance EventEmitter wakeup), per-session worker capacity,
   remote cancel protocol over the SSE channel.