feat: write up proposal for blob support

[Gozala]

No description provided.

[seefeldb]

yes, let's align. listing out what we currently have:

"Cell Link": (mutable redirect)
{ cell: { "/": entityId }, path: string[], [space: spaceDID], }
"Alias": (behaves like a query, transparent to writes)
{ $alias: { cell: { "/": entityId }, path: string[], [space: spaceDID], [schema: JSON Schema] } }Charm: Has$TYPE` field + argument, resultRef

So want:

• blob (has mime type)
• file (like blob, but has a filename)
• link
• alias
• "charm", primarily this points a recipe (spell) that explains how data is generated <-> this goes together with "source[s]" annotations on entities, which essentially say look there to see how i am computed
• "backlink" / "join"-ish to make a collection. "all the entities that point to entityFoo/path (& maybe more conditions)" with "point here" as special case
• "spread operator" simulate { ...otherThing, key: value } or [ ...otherList, myAddedItem]
• "this entity is about that other entity" annotation

{
   "/": {
       "link-v1": {
          doc: ...
          path: ...
       }
   }
}

just an "/":

{ "/": { "/": { ... } }

Blob:

{ "/": { "blob-v1": {
  type?: "image/png", // default octet...
  content: { "/": { "bytes": "...." },
}}

Blob:

{ "/": { "file-v1": {
  type?: "image/png", // default octet...
  name: "filename",
  lastModified?,
  content: { "/": { "bytes": "...." },
}}

[Gozala]

{
  'picture:sntdh34s5h': {
     'this/cfc-labels': {
      },
      'this/scheduling': {
      },
     'image/png;metadata': {
         name: 'profile.png'
         //....
     },
     'image/png': {
       'cause....': {
           is: '/': {
              'bytes': '....'
           }
       }
     }
  }
}