hive-sh4re: split inbox, container, journal, and schedule wire shapes into their own modules

Closes the #3110 split — lib.rs is now just the crate doc comment and
the pub mod list.

journal.rs's new doc comment fixes a pre-existing bug: the old
JournalPriority doc text in lib.rs was actually half Capability's doc
(a leftover from an earlier reorder that moved the code but not the
comment above it).

hive-sh4re/src/container.rs

@@ -0,0 +1,78 @@
+//! Container/agent-roster wire shapes: what `ListDescendants` and
+//! `HostRequest::AgentStatus` return, plus the per-account matrix
+//! identity shape surfaced by `GetAgentMeta`.
+
+use serde::{Deserialize, Serialize};
+
+/// One entry in a `ListDescendants` result.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ContainerInfo {
+    /// Logical agent name (no `h-` prefix).
+    pub name: String,
+    /// Whether the container is currently running.
+    pub running: bool,
+}
+
+/// One row in a `HostRequest::AgentStatus` result — the operator-CLI
+/// projection of the dashboard's per-agent `ContainerView`. Carries the
+/// agent's running/health flags plus the technical state an operator
+/// wants in a roster overview (`hivectl list-agents`).
+//
+// Four orthogonal, independently-observed facts about one agent, each
+// rendered as its own column/token by `hivectl list-agents` and read
+// individually by `--json` consumers. Any combination is meaningful
+// (a stopped agent can be paused and need an update), so folding them
+// into a state machine or nested flag structs would only add
+// `serde(flatten)` indirection to preserve the same flat JSON. Same
+// rationale as `LifecycleScope` in hive-host-sock.
+#[allow(
+    clippy::struct_excessive_bools,
+    reason = "flat wire projection of independent per-agent flags"
+)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct AgentStatusRow {
+    /// Logical agent name (no `h-` prefix).
+    pub name: String,
+    /// Whether the container is currently running.
+    pub running: bool,
+    /// Config commit is pending — the locked rev differs from the
+    /// agent's proposed/applied config (a rebuild would change it).
+    pub needs_update: bool,
+    /// The agent has no live claude session and is parked waiting for
+    /// the operator's re-auth flow.
+    pub needs_login: bool,
+    /// First 12 chars of the sha the meta flake currently has locked for
+    /// this agent's input. `None` when the agent has no locked rev yet.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub deployed_sha: Option<String>,
+    /// Count of this agent's pending reminders.
+    #[serde(default)]
+    pub pending_reminders: u64,
+    /// The agent's turn loop is parked (pause marker present in its
+    /// harness dir): the container may well be up and serving, it just
+    /// drives no turns. Orthogonal to `running` — an agent can be
+    /// paused while stopped, and pause survives a restart.
+    #[serde(default)]
+    pub paused: bool,
+    /// Parent in the topology tree. `None` marks a root-level agent.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub parent: Option<String>,
+}
+
+/// One matrix identity an agent can act as, surfaced in `GetAgentMeta`'s
+/// `matrix_accounts`. Field names match the daemon's `matrix-accounts.json`
+/// snapshot (written by `hive-matrix-mcp`'s account registry) so hive-c0re
+/// deserializes the snapshot straight into `Vec<MatrixIdentity>`; the
+/// snapshot's `live` / `is_primary` fields are ignored here (only live
+/// accounts are listed).
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct MatrixIdentity {
+    /// Logical account name (the `account` arg on the matrix MCP tools).
+    pub name: String,
+    /// Matrix user id (`@user:server`). `None` if the session restored
+    /// without a known user id yet.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub user_id: Option<String>,
+    /// Homeserver base URL this account is on.
+    pub homeserver: String,
+}