fix(studio): survive damaged package meta; clean up OPFS write husks#116
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The studio bricked on load in iOS Safari with "missing session: library: meta: parse meta: expected value at line 1 column 1": a damaged (zero- filled) /.lp/meta.json. The history event log tolerates such damage (it reads as empty), which routes PackageHandle::load into the strict read_meta origin fallback — one unparseable provenance sidecar then permanently fails every project open. Two fixes: - read_meta parses leniently: damage logs a warning and reads as absent; origin_event_for(None) already falls back to a Created origin. - opfs write_file removes the empty husk it created when the stage-and-swap fails on a file that did not previously exist. The createWritable atomic swap only protects content — getFileHandle (create: true) makes the entry immediately, so a tab jetsammed mid-flush (common on iOS) persisted a lie. Verified: lpa-studio-core suite (453 tests), lpa-fs-opfs real-browser OPFS suite (18 tests via chromedriver), wasm32 check, just check. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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Summary
missing session: library: meta: parse meta: expected value at line 1 column 1. Chain: a damaged (zero-filled)/.lp/meta.json+ an event log that tolerates the same damage (a garbage log reads as empty via the torn-tail drop) routesPackageHandle::loadinto the strictread_metaorigin fallback — one unparseable provenance sidecar then permanently fails every open of that project, including boot-time session restore.read_metanow parses leniently: damage logs a warning and reads as absent (origin_event_for(None)already falls back to aCreatedorigin). Provenance is a best-effort sidecar and should never be load-bearing — this matches the existing leniency in the event log and the gallery's skip-bad-cards behavior.write_fileinlpa-fs-opfsnow removes the empty husk it created when the stage-and-swap fails on a file that did not previously exist. ThecreateWritableatomic swap only protects content;getFileHandle(create: true)makes the entry immediately, so a tab jetsammed mid-flush (common on iOS) could persist an entry whose content never committed.serde_jsonsayscolumn 1(notcolumn 0/EOF), i.e. the file had non-JSON content — the zero-filled signature of size-persisted-but-content-lost, consistent with WebKit OPFS durability behavior under process kill.Validation
meta.jsonboth read as absent.cargo test -p lpa-studio-core: 453 passed.just lpa-fs-opfs-test(real Chrome + real OPFS via chromedriver): 18 passed across the three suites, exercising the reworkedwrite_filesuccess path end-to-end. (The failure branch is not exercisable in Chrome, whosecreateWritabledoesn't fail on demand.)cargo check -p lpa-fs-opfs --target wasm32-unknown-unknown,just check: clean.Contribution Terms
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