[tiny-modules] tinyskills: move scaffolding, fetch/scan retry and discovery walking into tinyskills #7577

Parent: #7532

Context

The module defines the ⟦tj:<hash>⟧ recovery marker and owns the declarations of the juice_* tools. The host still parses the marker itself, in normalize_handle and classify_handle_arg. It also defines the tool-name strings locally: RETRIEVE_TOOL_NAME, LEGACY_TINYJUICE_RETRIEVE_TOOL_NAME and REPL_TOOL_NAMES.

What moves

• crates/openhuman-core/src/inference/tokenjuice/repl_tools.rs (399): normalize_handle (160), HandleArg (173), classify_handle_arg (182) + tests
• crates/openhuman-core/src/inference/tokenjuice/mod.rs (438): RETRIEVE_TOOL_NAME (19), LEGACY_TINYJUICE_RETRIEVE_TOOL_NAME (20)
• repl_tools.rs:14 REPL_TOOL_NAMES

What stays in OpenHuman

• ModuleReplTool / TokenjuiceRetrieveTool impls and artifact authorisation
• MlHost callback (generate.rs, modules/tokenjuice_host.rs), install from config, RPC (schemas.rs, config_patch.rs)

Upstream target

• Repo tinyhumansai/tinyjuice, crate tinyjuice-bus: handle::{parse, classify} pure functions and tools::{RETRIEVE, LEGACY_RETRIEVE, REPL_TOOLS} constants beside repl_tool_declarations; bump contract version.
• Tracks tinyjuice#59.

Host adapter after the move

Host tools call tinyjuice_bus::handle::* and reference tool names via bus constants; ~15 agent/harness files that match on juice_* names switch to the constants.

Acceptance criteria

• Iterate locally against the on-demand compiled module (E0 [tiny-modules] E0: module source modes — load modules from release, linked or source build (no release per change) #7524 linked/source modes are for local dev and testing only, never CI)
• Upstream PR merged in tinyhumansai/tinyjuice first (fmt, clippy -D warnings, tests, coverage gate)
• Submodule release published; registry record (version, release_url, every PlatformAsset digest copied verbatim from the release's checksum.toml) and gitlink re-pinned to that release before this OpenHuman PR's CI can pass (node scripts/ci/check-module-pins.mjs)
• Tests that exercise only the moved logic move with it; host-adapter / composition tests stay here
• Old core code and its tests deleted in the same PR — no shim, re-export or alias left behind
• No contract type redeclared in OpenHuman; members called through tinyjuice-bus constants; contract version bumped if the bus changed
• scripts/ci/module-boundaries.json / docs/module-boundary-inventory.md updated
• pnpm rust:layout, cargo check --manifest-path Cargo.toml, cargo check --manifest-path crates/openhuman-app/Cargo.toml, affected pnpm debug rust <filter> green
• Regression test proving the behaviour is unchanged end-to-end through the host adapter
• Regression test: handle parsing accepts/rejects the same inputs (marker, bare hash, legacy forms) before/after; rg '"juice_(retrieve|find|extract|summarize)"' crates/openhuman-core finds no literals outside tests

Depends on

#7524 (E0 module source modes, for local iteration)