Reject special files without blocking, cap the properties payload at 1 MiB before allocation, and verify descriptor extent and the selected name. Preserve Latin-1 data, selected symlinks, physical filesystem facts, completed observations and exact failed-close ownership.
Reuse the stable bounded reader for profile artifacts and consolidate Ghidra file failure projection. Distinguish missing-at-open from disappearance or read failure, and attribute typed prerequisite failures at the consuming operation.
Validation: 384 focused tests across 14 files, 42 seed/extension controls, 32 final metadata/profile/CLI controls, check:fast and docs:check. Controlled macOS file/process fixtures; no real Ghidra/JVM or Windows/Linux lifecycle verification.
Bounded FIFO reproduction: baseline direct and public doctor required external cleanup around 2.2s; candidate returned independently around 0.4/0.57s, all fixture groups verified empty. Warm normal doctor baseline/candidate: elapsed 1.211/1.230s, CPU 1.239/1.247s, sampled family RSS 524/524MB, reply tokens 3116/3116. No performance improvement claimed; true cold and whole-agent costs unmeasured.
Refs #4672
Return a closeable owner before prerequisite work begins. Share creation across independent callers, join the final departure and late handoffs, retain exact failed resource owners, and gate operation dispatch again after acquisition.
Keep reuse admission separate from native health. Move shared provider ownership below application workflows and consolidate failure attribution; remove the superseded lazy client.
Validation: 34 focused owner, lazy, composite and session controls; check:fast. Compiled baseline/candidate recording-provider workflow reproduces then fences dispatch after close. No native provider claim.
Refs #4561, #4667
morluto