[ffumero2003]

Version 0.10.0

Release-prep PR per RELEASE.md. ⚠️ Do not tag or merge until the release gate is cleared (see below).

This is the Version 0.10.0 commit — changie-batched changelog and version strings. It changes exactly the four RELEASE.md paths, nothing else:

• CHANGELOG.md — new ## [0.10.0] section + compare link
• base/base.go — DefaultUserAgent = "blazer/0.10.0"
• bin/b2keys/go.mod — require github.com/Backblaze/blazer v0.10.0
• .changes/ — 57 fragments batched into .changes/v0.10.0.md

Contents

12 Added (the new parity capabilities), 11 Breaking Changed, ~30 Fixed, 1 Security. Full notes in .changes/v0.10.0.md / CHANGELOG.md. Every breaking entry is prefixed **Breaking:** so the migration list reads off the changelog directly.

Release gate — make release-check currently HOLDS (3 items)

Finding	What it is	How to clear	Owner
CodeQL #9 go/incorrect-integer-conversion @ base/base.go:2043	False positive. The line is the 32-bit fix from #370: int(min(contentLength, maxInt, int64(^uint(0)>>1))). The min(...) already bounds the value to the platform's max int, so the int() cast cannot truncate — CodeQL's query just doesn't track the bound.	Code-owner dismissal with that reason, or a small defensive guard.	code owner
govulncheck GO-2026-6599 (html/template)	Go standard-library vulnerability, fixed in Go 1.27.2. The local gate ran on Go 1.27.1. Not a repo code issue.	Re-run make release-check with Go ≥1.27.2 (CI already tests on 1.27.3).	release manager
Secret scanning	UNVERIFIED — the API was not readable with the current token (404). Per RELEASE.md this never passes silently.	Check the Security tab by hand (needs security access).	code owner

Verification

• changie batch auto + changie merge → exactly the 4 paths above, no stray changes.
• make ci: PASS — build, vet, gofmt, lint (0 issues), full -race suite, b2keys, all 5 cross-compiles, changelog-check, script tests.
• Full -race -count=1 ./base ./b2/... ./x/... on merged main: green.
• Live blazer-go-demo sweep against real B2: all 19 capabilities verified working (incl. the fix(base): preserve nested authorization capabilities in AuthData #358 auth fix). The 2 non-green demo subcommands were harness-side (a destination-bucket precondition and an unstageable >5 GB copy case), not blazer defects.

To release, after the gate clears (per RELEASE.md)

1. Clear the 3 gate items above.
2. Approve + merge this PR (squash/rebase — main requires linear history).
3. Tag the merge commit v0.10.0 and push it.
4. gh release create v0.10.0 --notes-file .changes/v0.10.0.md.
5. Prime the Go proxy and confirm pkg.go.dev shows the version.

Gremlins mutation testing is intentionally not in this release (parked in #332); the mutation-found tests remain.