Ess 0.4.2

Tooling only — the framework itself is unchanged. 1_Ess.lua is byte-identical to 0.4.1's apart from the
version string and the build stamp; src/ has no functional change in this release. If you only install the
framework, this release gives you nothing new and there is no reason to update. It is versioned at all because
the release zip now carries a new file.

What's new is node definitions for the visual editor, generated from the API and enriched by hand. The
node-graph editor at visual.mercs2.tools is how most beginners will meet this
framework, and its ~200 nodes were hand-written against src/*.lua — accurate, but maintained by memory. This
generates them from ess.json instead, and pairs that with a hand-authored overlay carrying the thing a
signature can never carry: what a parameter is for, what units it's in, and which of them will silently do
nothing.

486 nodes, every one enriched by hand against the real source, with all 896 parameters carrying a
confirmed type, a working default and an explanation — plus 62 functions deliberately skipped, each with a
written reason. 93 of the nodes are the Ess.Easy.* beginner tier; 138 are pure getters that wire into other
nodes' inputs.

Nothing in the editor's own repo is touched. This produces the data; adopting it is a separate, deliberate step.

Added

• build/nodes.py — merges dist/ess.json (what exists) with api/nodes.overlay.json (what it means)
  into dist/nodes.json, plus dist/ess-nodes.generated.js, a working litegraph consumer that proves the data
  is sufficient. --check is a drift gate; --report shows coverage.
• api/nodes.overlay.json — the hand-authored half. The overlay cannot invent anything: every entry is
  validated against ess.json, so one naming a function that doesn't exist, or giving a function a parameter it
  doesn't have, fails the build. It adds meaning to a real signature and can never add a signature.
• build/merge_overlay.py — assembles per-namespace overlay fragments, validating before writing and
  rejecting overlaps, invented names and bad types rather than absorbing them.
• tools/test_nodes.js — executes the generated nodes against a stubbed editor and asserts the Lua they
  produce. No browser, no editor checkout, no game. The load-bearing check is that a guid parameter is
  spliced raw rather than quoted: a quoted handle produces Lua that runs, logs nothing and does nothing —
  exactly the silence Ess.DEBUG exists to fight, and not something a beginner should have to diagnose.
• api/README.md — what each manifest answers, the type vocabulary, and how to consume nodes.json.
• CI gates for all of it, and api/nodes.json in the release zip.

Fixed (all in the new tooling, not in the framework)

• Multi-value returns were structurally impossible as getter nodes. A getter splices its call inline as an
  expression, and Lua truncates a multi-value call to one value unless it is last in a list — so
  Ess.Color.hex would have silently delivered r and dropped g and b. Such functions are now
  auto-promoted to action nodes that capture into one local each. 26 functions were affected. (The
  editor's own convention was to skip these; this recovers them instead.)
• Method-style calls were emitted wrong. function Ess.RNG:int(n) desugars to Ess.RNG.int(self, n), so a
  dotted Ess.RNG.int(5) passes 5 as self and leaves the real argument nil — no error, just a wrong answer.
  21 functions across Ess.Track, Ess.RNG and Ess.SaveVar. They now get a synthetic receiver input and
  emit Ess.RNG.new():int(5). Both have regression tests.

Notes

• Node type ids are prefixed essgen/, never ess/. The editor's hand-written nodes own ess/; sharing
  the prefix would silently overwrite hand-tuned nodes depending on script load order. Both coexist, so an
  editor can migrate one namespace at a time on purpose rather than all at once by accident.
• Descriptions ship in two lengths — desc_short for a tooltip, desc for a details pane — because the full
  ones carry engine traps worth several sentences (a helicopter running combat AI ignores a land order; a
  pursuit cap is one-way for the whole session) and those don't belong in a hover.
• A multi-return spill gate was added to --check after one batch spotted that a bare
  Ess.Player.targetUnderReticle(0) default would spill three extra arguments into the following parameter.
  It immediately caught two more instances in a later batch that had been missed.