[senamakel]

Summary

• Delegate memory binding, cache reuse/invalidation, rooted layouts, scrubbing and timing to TinyMemory's EngineBinder; delete the runtime memory/guard.rs implementation.
• Keep host endpoint/engine selection, keyring access and profile/SaaS gates. Pass security::scrub::host_policy() for configured, profile, installed and test engines.
• Add the optional, object-safe backend memory bearer port. TinyHumans supplies native CallbackBearerSource with credentials resolved per request; standalone explicit-endpoint configurations retain the shared safe credential resolver.
• Consume merged TinyMemory PR #38 at gitlink 8c9a2e1, including the public installed-engine getter. Preserve openhuman.memory_*, memory, and flow_memory_* identifiers.
• Keep the guard regression adapters in external test files with the original memory::guard::tests names.

Verification at 5113d06a

• Root/app/SDK/Embed cargo check: passed.
• SDK and Embed strict default all-target Clippy: passed.
• Core normal/strict default all-target Clippy: reproduced the exact Host96 baseline (normal: 1 error + 39 warnings; strict: 40 errors), across the same unchanged source files. These are recorded inherited failures, with zero new diagnostics.
• Channels-disabled compile and dependency-shed checks: passed.
• Workspace formatting and edition-2021 checks on touched Rust files: passed.
• Complete pnpm rust:layout (layout, crate chain, storage bypass and storage owner): passed.
• pnpm debug rust memory: 568 passed, 118 target groups, largest library group 514; 0 failed, 0 ignored. The initial missing ws setup was fixed with the frozen root pnpm install; source and lockfiles remain unchanged.
• Final instrumented run: 417 unique host tests passed, all 30 required canonical cases exactly once, 0 failed and 0 ignored.
• Changed production coverage: 79/84 lines (94.05%), every executable changed file above 80% (minimum 91.38%). diff-cover 10.6.0 passed at 94% over the complete patch (441/468 lines). Reports use 17 fresh profiles from all six test groups and the exact three executed test binaries.

All actual pre-push hooks passed (formatting, frontend lint, TypeScript compilation, production Rust Clippy, and command/UI token checks); the validated source tree remained unchanged.

The retired host timing-helper contract maps to two executed tests from merged TinyMemory PR38: timing_failure_outcome_is_the_stable_error_code_only and external_binding_times_every_async_method_without_logging_payloads. Those native executions are not counted as host tests.

Refs #95
Part of tinyhumansai#8000

Hosted soft checks: submission checklist, coverage matrix and AppImage checks passed. Markdown links reproduced the two unchanged canonical-main 404s in docs/gitbooks/en/developing/architecture/agent-harness.md (loader.rs and stop_hooks.rs); the reference lines are identical to the epic base. Automated reviews, inline threads and top-level comments were empty after CI completed.