[techflag]

Upgrading DSH previously left old managed workbenches throwing workbench/incompatible-host during activation, which blocked the complete official Web boot and made the platform repair UI unreachable. Preserve verified incompatible registrations as disposable, blocked lifecycle bindings: they receive no business registry entry or Client page, while the native shell and platform remain available for repair. Invalid callers, changed installation bytes, mismatched declarations and ordinary errors still fail; bundle selections, plugin files and user data are not rewritten.

Successful browser_close and information-only browser tools previously counted as page activity in the owned browser presentation layer. The legacy observer could also request a screenshot after close, recreating an empty page and reopening the task panel. Classify page activity, closure and unchanged diagnostics separately; withdraw only the matching Session browser tab, cancel obsolete captures, and reject stale activity and selection responses so neither cleanup nor late replies can reopen a manually closed view. Normal browser navigation remains supported.

Desktop and Web now use the single official DSH npm Host/Client/SDK graph at 0.2.1-rc.2. Regenerate the actual official client inventory (including the new model-label component), align owned runtime descriptors, and retain the authorized two exact-checksum native Conversation frame seams. Desktop becomes 3.0.0-alpha.2; the unpublished alpha.1 tag is not moved.

Binary archives have explicit, independent provenance. Apple Silicon and Windows use official rc.2 archives. Upstream has no Intel rc.2 archive, so Intel uses the explicitly locked official rc.1 Node/pnpm/Python/Office/command resources while every actual DSH npm package stays rc.2. Preserve upstream metadata and verify source version, URL, size, SHA-512 and metadata receipt through extraction and final Resources, with no guessed URL, automatic fallback or relabeling.

Validation:

• Shared Web build/types/version checks; Workbenches 313/313, Skills 30/30, Quality 346/346.
• HEAD 6861f09 CI Web source checks passed, including 20/20 browser display lifecycle regressions and 1/1 real managed Chromium Session integration.
• Desktop 164 passed + 22 Node passed, with two platform-specific skips; actual inventory/provenance controls passed.
• A real Cordis Host/Client integration packs and installs archive bytes, verifies the retained digest, crosses the authenticated registration RPC, rejects incompatible pages and completes the plugin graph and disposal.
• Baseline actual arm64/x64 packages passed full Resources Host checks (six required services, no writable Profile node_modules, 303 npm DSH instances all rc.2). Intel additionally executed Node/pnpm/Python, Office write/read roundtrips and CLI checks under Rosetta.
• Final HEAD 6861f09 was exercised in an actual packaged macOS arm64 Desktop using the existing test Home. Both original trips and itinerary details survived replacement/restart. A temporary Hangzhou expense changed budget/spent/remaining from 1000/300/700 to 1020/310/710; confirmed deletion restored the original totals. Todo completion changed 1/1 → 0/1 → 1/1. The separate Chengdu trip retained its itinerary, todo and 80/60/20 totals throughout. An incompatible older managed workbench did not block the shell.
• Switching the official rc.2 appearance setting to light mode left the actual business list readable and both original trips present.
• The exact native close-only reproduction also passed in that packaged Desktop: native turn 4 executed one browser_close call (sequence 714), completed in 4 seconds, and left no task-browser tab, URL or controls. Both the accessibility tree and the actual Desktop screenshot confirmed that the complete official Conversation and Workbench stayed present. This is a browser-cleanup regression test, not an AI application creation-time claim.
• Current workbench version 0.1.1 has passed the direct GUI/data checks above but has not yet received a new platform trial confirmation. The earlier version 0.1.0 completed its eight-item checklist; that confirmation is not carried forward as acceptance of 0.1.1.
• CI run 39106737710 at HEAD 6861f09 completed successfully: shared checks, Web source checks, enterprise packaging, Windows x64 packaging and macOS x64/arm64 packaging all passed. The travel workbench is a generated business application, not a preinstalled platform bundle; its current-version trial confirmation remains pending as stated above and is not an additional platform release gate.

This isolation applies to verified managed registration compatibility failures; it does not claim to contain arbitrary third-party top-level import or ABI failures. Existing third-party plugins pinned to older DSH remain a documented upgrade limit, without automatic disabling/deletion or bypass. Raw test evidence, credentials and generated installers are not committed.