feat(buckets): add fork rebase and merge commands

[designcode]

What

Adds two fork operations to the buckets command group, on top of the new rebaseFork/mergeFork APIs in @tigrisdata/storage 3.17.0 (dependency bumped ^3.16.0 → ^3.17.0):

• tigris buckets rebase <fork> — advance a fork onto the latest state of its source bucket.
• tigris buckets merge <fork> [--into <source>] [--from-snapshot <snap>] — merge a fork's changes back into its source. The source is auto-resolved from the fork's parent (getBucketInfo → forkInfo.parents[0]) unless --into is passed.

Both confirm before mutating (skip with -y/--yes, guarded in non-TTY), print the resulting snapshotVersion, and support --json.

Also makes the already-supported stdin path of objects put discoverable — the description and examples now show that object data can be piped in (echo 'hi' | tigris objects put t3://bucket/key). Docs/spec only, no behavior change.

Testing

Integration tests added to test/cli.test.ts, passing against the live backend:

• rebase a fork onto its source
• merge a fork with auto-resolved parent
• objects put from piped stdin (round-tripped via objects get)

tsc, ESLint, and Prettier all clean; the default unit suite is unaffected.

🤖 Generated with Claude Code

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Note

Medium Risk
Merge and rebase mutate bucket state on the live backend; mistakes could affect source buckets, though confirmations and explicit --yes in scripts mitigate operator error.

Overview
Adds tigris buckets rebase and tigris buckets merge wired to @tigrisdata/storage3.17.0 (rebaseFork / mergeFork). Rebase updates a fork from its source; merge writes fork changes into the source, with optional --into, --from-snapshot, interactive confirm (skippable with --yes), and --format json. Merge defaults the target to the fork’s parent via getBucketInfo when --into is omitted.

src/specs.yaml documents both commands and updates objects put to describe stdin piping (examples only; no upload behavior change in this diff).

Integration tests cover rebase, merge with auto-resolved parent, and objects put from piped stdin via a new runCliWithStdin helper.

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