fix: avoid missed logs when streaming startup logs (#8029)

* feat(coderd,agent): send startup log eof at the end

* fix(coderd): fix edge case in startup log pubsub

* fix(coderd): ensure startup logs are closed on lifecycle state change (fallback)

* fix(codersdk): fix startup log channel shared memory bug

* fix(site): remove the EOF log line

coderd/apidoc/docs.go

@@ -5856,6 +5856,9 @@ const docTemplate = `{
                 "created_at": {
                     "type": "string"
                 },
+                "eof": {
+                    "type": "boolean"
+                },
                 "level": {
                     "$ref": "#/definitions/codersdk.LogLevel"
                 },
@@ -9378,6 +9381,10 @@ const docTemplate = `{
                     "type": "string",
                     "format": "date-time"
                 },
+                "eof": {
+                    "description": "EOF indicates that this is the last log entry and the file is closed.",
+                    "type": "boolean"
+                },
                 "id": {
                     "type": "integer"
                 },