feat(cli): kind-aware shared-collection reconcile + string-or-table manifest (§11.6 docs C4)

Make the declarative collection surface carry a `kind` so docs (and future
kinds) are declarable. Back-compatible: the shipped `collections = ["catalog"]`
form still means kv.

- manifest: `collections` entries are now `CollectionDecl` — an untagged enum of
  a bare string (kv shorthand) or a `{ name, kind }` table (kind ∈ kv/docs).
  `Manifest::collections()` normalizes to `(name, kind)` pairs; build_bundle
  emits `[{name, kind}]`. Still `[group]`-only. Unit test covers the
  string-or-table mix + app rejection.
- apply: `Bundle.collections: Vec<CollectionSpec>` ({name, kind=default "kv"});
  `CurrentState.collections: Vec<(name,kind)>` via list_all_for_owner;
  `diff_collections` keys each change by name with `detail = kind` and identity
  `(LOWER(name), kind)` (so a kv and a docs collection of the same name are
  distinct); reconcile reads the kind from `detail`; state_token folds
  `coll|{kind}|{name}`; validate_bundle rejects unknown kinds + dups by
  (name,kind); `collection_report`/CollectionInfo + `pic collections ls` gain a
  kind column.

Existing kv journeys + nearest-wins still green (the bare-string form normalizes
to kind=kv end to end).

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

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

@@ -163,7 +163,11 @@ pub fn build_bundle(manifest: &Manifest, base_dir: &Path) -> Result<Value> {
         "secrets": manifest.secrets.names,
         "vars": vars,
         "extension_points": manifest.extension_points(),
-        "collections": manifest.collections(),
+        "collections": manifest
+            .collections()
+            .into_iter()
+            .map(|(name, kind)| json!({ "name": name, "kind": kind }))
+            .collect::<Vec<_>>(),
     }))
 }