feat(cli): pic projects ls + §7 M3/track-complete docs

§7 M3 (part 3) — the ownership track becomes inspectable, completing M1–M3.

- server: GET /api/v1/admin/projects (projects_api) lists every project + its
  owned-group count (projects repo list_with_counts, one GROUP BY); behind the
  /admin middleware, like the groups list.
- CLI: pic projects ls (cmds/projects.rs + client projects_list); the
  apply_ownership plan-preview journey now also asserts projects ls (plat owns
  exactly 1 group; teamb listed).
- docs: design §7 + CLAUDE.md record M3 shipped and the whole §7 multi-repo
  ownership track (M1 claim · M2 attach ceiling · M3 preview + projects ls)
  COMPLETE; deferred = structural-divergence + declarative tree shape + per-env
  approval gating.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/picloud-cli/src/cmds/mod.rs

@@ -16,6 +16,7 @@ pub mod logout;
 pub mod logs;
 pub mod members;
 pub mod plan;
+pub mod projects;
 pub mod pull;
 pub mod queues;
 pub mod routes;

crates/picloud-cli/src/cmds/projects.rs

@@ -0,0 +1,29 @@
+//! `pic projects` — read-only view of §7 multi-repo ownership projects.
+//!
+//! A project is the repo-root that declaratively owns a slice of the group
+//! tree. Ownership is CLAIMED by `pic apply` (first apply with a `[project]`
+//! slug registers it); this command only lists what exists.
+
+use anyhow::Result;
+
+use crate::client::Client;
+use crate::config;
+use crate::output::{OutputMode, Table};
+
+/// `pic projects ls` — every project + how many group nodes it owns.
+pub async fn ls(mode: OutputMode) -> Result<()> {
+    let creds = config::resolve()?;
+    let client = Client::from_creds(&creds)?;
+    let projects = client.projects_list().await?;
+    let mut table = Table::new(["slug", "name", "owned_groups", "created_at"]);
+    for p in &projects {
+        table.row([
+            p.slug.clone(),
+            p.name.clone(),
+            p.owned_groups.to_string(),
+            p.created_at.to_rfc3339(),
+        ]);
+    }
+    table.print(mode);
+    Ok(())
+}