Warn, don’t strip, binary-token GDScript exports

Godot’s default Script Export Mode (Binary tokens / compressed, 4.3+) compiles every .gd to .gdc in the built-in EditorExportGDScript plugin, which is registered before any addon and saves the .gdc + breaks the per-file export loop before export_strip.gd runs. So addon and extension scripts ship as compiled .gdc in any binary-token mode. The natural fix — pre-excluding the addon in _export_begin — is blocked: EditorExportPreset.set_exclude_filter is not bound to GDScript (still unbound in 4.6 — godotengine/godot#4054).

Decision: warn, do not strip. export_strip.gd detects the leak by observing which of its own _export_file calls fire — a binary mode never delivers the addon/extension .gd (the built-in tokenizer consumes them first), only the addon’s non-script files — and emits an export-time warning: EditorExportPlatform.add_message() on 4.4+ (export dialog), push_warning() on 4.3 (Output log). A non-script-file guard suppresses the warning when the user has already excluded the addon (no false positive). Godot 4.2 has no binary-token mode (scripts ship as text and are stripped), so it never warns. The detection is version-agnostic — it reads no preset state, so it works on 4.3 where get_script_export_mode() is unbound.

The leak is cosmetic: the shipped scripts are orphaned (their editor-only loader is stripped) and GDScript loads lazily, so they are never parsed or executed. A runtime-safety audit confirms no runtime path reaches them — no add_custom_type, no resource loaders, no static-init; the runtime autoload is nulled in every export and additionally self-gates on not OS.has_feature("editor") (false in every export template, debug and release). The cost is dead weight in the PCK plus revealing that MCP tooling was used — and even a perfect strip cannot hide the latter (global_script_class_cache.cfg embeds addon paths as plaintext). The inert [mcp_toolkit] ProjectSettings keys carried in project.binary (e.g. internal/bootstrap_complete) are a cosmetic fingerprint of the same class — no secrets (the auth token and registry live in user://, never packed) — left in place for the same reason; an optional settings strip is tracked as a high-priority post-1.0 idea (Plan/Ideas/PostRelease/2026-06-08-strip-mcp-toolkit-projectsettings.md).

The bug is 4.3+ only (binary tokenization was introduced in 4.3). Extends ADR 0005 (single-level extension discovery / strip): the warning counts the same single-level extension set. Full source-verified analysis (engine line references for 4.2–4.6): Insights/export-strip-binary-token-analysis.md.

Considered alternatives

File relocation during the bake (move addon .gd off disk in _export_begin, restore in _export_end). The only mechanism that actually strips, but rejected: it is an on-disk, persistent change whose recovery code lives inside the addon directory it moves, so a crash before _export_end leaves the addon broken with no self-heal; and moving plugin.gd / .uid mid-export risks breaking the export itself. The autoload-null we keep is in-memory only and self-heals; relocation is not.
.gdignore written at export time. Rejected: .gdignore is honored only during an EditorFileSystem scan, but the export file list is already built from the in-memory tree — a fresh ignore needs a rescan, and a mid-export rescan is the scan-collision crash class fixed in 41l-tricies. A persistent .gdignore would also hide the addon from the editor.
Addon self-adds to the exclude filter. Rejected: the clean version needs the unbound set_exclude_filter (#4054); the export_presets.cfg file-edit workaround is stale for the live in-memory preset, clobbered on the next editor save, inconsistent between editor and CLI exports, and invasively rewrites the user’s owned export config.
C#/GDExtension helper to call set_exclude_filter. Rejected: adds a binary, non-GDScript dependency to a GDScript-only AssetLib addon.
De-register the built-in GDScript export plugin during the bake. Rejected: would ship the user’s whole game as text, downgrading the script protection they chose; fragile global-registry mutation mid-export.