feat(update): 主机每日记录组件版本比对，面板更新页展示可用更新与应用命令

internal/updates/status.go

@@ -0,0 +1,45 @@
+package updates
+
+import "time"
+
+// StatusKey is the platform_settings key `felis update --record` writes the
+// newest version check to (felis-update-check.timer runs it daily on the host,
+// where the versions are readable); internal/api serves it to the panel. Felis
+// applies nothing on its own, so this record is how a SysAdmin learns an update
+// exists without opening a shell on the node.
+const StatusKey = "update_report"
+
+// StatusStaleAfter is how old the newest check may get before the panel says the
+// daily timer stopped: a day plus the timer's randomized delay and a margin.
+const StatusStaleAfter = 26 * time.Hour
+
+// Component states in a StatusReport.
+const (
+	StateCurrent    = "current"    // the newest stable release is installed
+	StateAvailable  = "available"  // a newer stable release exists
+	StateUnknown    = "unknown"    // the release feed could not be read
+	StateUnreadable = "unreadable" // the installed version could not be read
+	StatePinned     = "pinned"     // never proposed a change by policy
+)
+
+// StatusReport is the value stored under StatusKey.
+type StatusReport struct {
+	CheckedAt time.Time `json:"checked_at"`
+	// Felis is the version of the felis binary that ran the check.
+	Felis      string            `json:"felis"`
+	Components []ComponentStatus `json:"components"`
+}
+
+// ComponentStatus is one component's line of a StatusReport. Latest is empty
+// unless State is StateAvailable; Error names why a version is missing (State
+// StateUnknown or StateUnreadable); Selector is the `felis update --<selector>`
+// flag that prints how to apply it, empty for a component with none.
+type ComponentStatus struct {
+	Name     string `json:"name"`
+	Current  string `json:"current,omitempty"`
+	Latest   string `json:"latest,omitempty"`
+	State    string `json:"state"`
+	Selector string `json:"selector,omitempty"`
+	Note     string `json:"note,omitempty"`
+	Error    string `json:"error,omitempty"`
+}