feat(booter): cache syscalls proc JSON, net tuning hints, /dev/shm unlink, POSIX/docs sync

- Cache /proc/bare_os/syscalls.json until warm read cache clear; invalidate with vfs.bareOsClearWarmReadCaches
- net_summary: optional udxTuning / hyperswarmTuning from BARE_OS_UDX_* / BARE_OS_HYPERSWARM_* JSON
- Metric: operator.corestore_snapshot_hint on bareOsCorestoreSnapshotHint
- pathconf: _PC_NAME_MAX 128 under /dev/shm
- vfs: fix unlink for /dev/shm segments; add roundtrip test
- protocol: bareOsIsAllowedSeedRpcMethodShort + tests
- getconf: _POSIX_SHARED_MEMORY_OBJECTS, _POSIX_MESSAGE_PASSING, _POSIX_ASYNCHRONOUS_IO + test
- microbench: syscall suite (syscalls proc JSON stringify)
- JSON Schema bare-os-syscalls.schema.json schemaVersion 5; posix-conformance-matrix ops = getconf
- Docs: blind-relay security note, compat matrix (1.38.0 / 1.0.4), handbook 04/09, appendix, OTA note
- Pear: document host coupling in compatibility-matrix (no pear-runtime manifest entry)

kernel/lib/init/init-main.js

@@ -2822,6 +2822,11 @@ async function printSessionBanner(ctx) {
 }
 
 /**
+ * Trusted post-boot checks. **`BARE_OS_SELFTEST_FORMAT=tap`** and **`junit`** emit diagnostics on
+ * **`ctx.console.error`** (this function destructures **`ctx.console`** as **`console`**) so output
+ * follows the Test Anything Protocol’s stderr convention while staying on the booter session sink—
+ * not **`globalThis.console`**. Plain **`selftest:`** lines use the same sink.
+ *
  * @param {Record<string, unknown>} ctx
  * @returns {Promise<boolean>}
  */