[ejgallego]

Adopt the qualified public VIR dependency/runtime pair in the isolated vir/ project and replace the host's local unfolding of RuntimeM with supported IO exports. Use RuntimeM.run only for creation and recovery of the opaque JSL session. This is a dependency update and public-API cleanup; Bench/Life already worked, and RuntimeM.run was available at the previous pin.

Pin producer bf8b6a80a5d4011ffd6804fb7a395b9cd2d0d668 and Lean 4.36.0-rc1. Its tracked resource lock selects public runtime content 0d7d7edd3dde264439803e247dab0376116d5527d280359a67f80980e715bea6. Update the toolchain documentation and label existing performance ratios as historical.

The four export names and flat command-packet results stay compatible with the existing JavaScript adapter. Both JavaScript files are byte-for-byte identical to upstream main. This PR targets main independently of #9; lifecycle integration and byte effects are separate work.

Validation:

• The migrated host checks with no errors or warnings through lean-beam on the pinned compiler.
• vir/build.sh bench life builds and publishes both applications with the matching public runtime.
• Chromium 145 and Firefox 146: Life reaches generation 100, 53 live cells, board hash bdbe4aa6; all nine keyed-table operations match the vanilla lane after every operation.
• A no-op callback/take ABI smoke invokes an unallocated callback slot with a Unicode/NUL string. It checks successful invocation and an empty drain, not payload preservation through an application callback.
• Used the existing race assertions with VIR/vanilla lanes; the local driver also enables the normally Chromium-only table check in Firefox. No performance claim is made.
• Whitespace checks and workflow syntax lint pass. Full site/Roster/QED64 CI has not been run locally.