Size tiled nodes from their media instead of fixed boxes

{
  "backend": {
    "author": {
      "email": "drschwabe@fastmail.com",
      "name": "Derrick Schwabe",
      "time": 1789243925
    },
    "commit": "git:sha1:bf64a3d91e617cc78e77ccefdb46e10a6245443d",
    "committer": {
      "email": "drschwabe@fastmail.com",
      "name": "Derrick Schwabe",
      "time": 1789243925
    },
    "manifest": "mmm-manifest:sha256:cd0fca6ccc171a140c7d688b22fd1a94ca10667fabe18bd82110bb1959b2291a",
    "message": "Size tiled nodes from their media instead of fixed boxes\n\nTiled previews still fell back to invented bounds whenever a node lacked\na measured size: displaySize defaulted to 520x360, previewDisplaySize to\n320x260, and new nodes were created at 560 wide for maps and 360x390 for\ntilesets whatever they held. A 512x7936 atlas therefore arrived squashed\nto about two pixels a tile, which is too small to aim a selection at.\n\nPreviews now draw at one source pixel per mesh unit and only fit a\ndimension the node actually carries. An unsized side of the preview takes\nits extent from the canvas, so measuring it would just feed that size\nback; it is left unbounded instead, and the preview takes its natural\nheight rather than flex-1, which would collapse it to its padding.\n\nNew maps and tilesets, from the create menu, a Tiled import, or a JamPC\ncapture, are given only a width: their media plus the 18px preview frame.\nThe height then follows the 1:1 canvas until the node is resized. Import\nlayout advances by those real sizes rather than fixed rows, and resizing a\nmap re-renders it live as tilesets already did.",
    "objectFormat": "sha1",
    "parents": [
      "git:sha1:07fd4310918c81f32e875bbb47a2913c0001ebbc"
    ],
    "ref": "refs/heads/master",
    "summary": "Size tiled nodes from their media instead of fixed boxes",
    "tree": "git:sha1:d38850809d17ea7dc9f0ba16c126cac17adc13be",
    "type": "git"
  },
  "issuedAt": "2026-09-13T15:05:56.085Z",
  "previous": "mmm-revision:sha256:00b0c756fda3886cba6b066f110fe65c6732321a23b9d1c34682100085943eae",
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  "protocol": "mmm/0-alpha",
  "sequence": 195,
  "type": "mmm/revision"
}