[whizps]

Description of the problem being solved:

Players plan their atlas passive tree on separate websites today. This adds an Atlas tab (next to Party and Compare) for planning atlas trees inside Path of Building:

• Every atlas tree version: the official tree from 3.18.0 to the current league, including Ruthless, drawn from GGG's official export (https://github.com/grindinggear/atlastree-export).
• Planning: hovering a node shows the shortest path to it, clicking allocates it, and clicking an allocated node removes it and everything that depends on it. Undo/redo (Ctrl+Z / Ctrl+Y) work as usual.
• Variant notables: an effect dropdown appears when you allocate one.
• Highlighting: hovering a node highlights every node with the same name. For example, hovering a Gateway highlights its partner, and hovering a Breach cluster highlights every Breach cluster on the tree.
• Stats panel: the right-hand panel shows points used and all allocated stats, summed and grouped by mechanic, with collapsible categories. Generic stats go under Misc.
• Saving: several named atlas trees can be kept. They are stored once per user in AtlasTrees.xml next to Settings.xml and shown in every build, like the in-game atlas, which belongs to the account rather than a character. Changes save automatically.
• Sharing: import and export use the official link format. Exported links open on pathofexile.com.

Build calculations are untouched. No calc, mod parsing or passive tree code is changed, atlas stats are never parsed into modifiers, and atlas edits never trigger a recalculation or mark the build as unsaved. Build files are not modified.

Changes to existing files:

• Build.lua: the button, the tab, the draw call, and a load-only <Atlas> section for build files from an earlier version of this feature. Saving with the Atlas tab open stores viewMode="TREE".
• Main.lua: the atlas version list and a cached main:LoadAtlasTree.

Adding new leagues: run python3 src/Export/Atlas/import_atlas_tree.py --tag <tag> and commit the result. The steps are in docs/atlas/importing-atlas-versions.md, and docs/atlas/README.md explains how the feature works. Images shared between leagues are stored once (src/TreeData/Atlas/Images/), so all 23 versions together add about 43 MB.

Steps taken to verify a working solution:

• New specs (spec/System/TestAtlas*_spec.lua) cover:
  • loading every version
  • pathing, removal and Gateways
  • variant notables
  • the atlas library file and importing from older build files
  • share link round trips
  • the stat summary
  • drawing and tooltips
• TestAtlasNonInterference_spec.lua loads every bundled test build with and without atlas data, allocates atlas nodes, and checks that every calculated output is identical and no recalculation is triggered.
• The full suite passes except TestRareLike_spec.lua, which fails the same way on dev without this change.
• Regenerating ModCache (REGENERATE_MOD_CACHE=1) gives no diff.
• The spellcheck using the project's cspell config reports 0 issues.
• Tested manually on Windows: planning and removing nodes, hover highlighting, the stats panel, and exporting a link that opens on pathofexile.com with the same nodes. Also run on Linux.

Link to a build that showcases this PR:

Not build-specific: open any build and click Atlas.

Before screenshot:

No Atlas button in the sidebar (new feature).

After screenshot:

[whizps]

I know this is a big PR. but this should not touch to much of the base files just add new functionallity.

And im using the official data from GGG for the tree. there's also instructions on how to maintain it upstream.