switches to go-ipfs-cmds@master after merging ipfs/go-ipfs-cmds#315

* feat(config): Import.* and unixfs-v1-2025 profile

implements IPIP-499: add config options for controlling UnixFS DAG
determinism and introduces `unixfs-v1-2025` and `unixfs-v0-2015`
profiles for cross-implementation CID reproducibility.

changes:
- add Import.* fields: HAMTDirectorySizeEstimation, SymlinkMode,
  DAGLayout, IncludeEmptyDirectories, IncludeHidden
- add validation for all Import.* config values
- add unixfs-v1-2025 profile (recommended for new data)
- add unixfs-v0-2015 profile (alias: legacy-cid-v0)
- remove deprecated test-cid-v1 and test-cid-v1-wide profiles
- wire Import.HAMTSizeEstimationMode() to boxo globals
- update go.mod to use boxo with SizeEstimationMode support

ref: https://specs.ipfs.tech/ipips/ipip-0499/

* feat(add): add --dereference-symlinks, --empty-dirs, --hidden CLI flags

add CLI flags for controlling file collection behavior during ipfs add:

- `--dereference-symlinks`: recursively resolve symlinks to their target
  content (replaces deprecated --dereference-args which only worked on
  CLI arguments). wired through go-ipfs-cmds to boxo's SerialFileOptions.
- `--empty-dirs` / `-E`: include empty directories (default: true)
- `--hidden` / `-H`: include hidden files (default: false)

these flags are CLI-only and not wired to Import.* config options because
go-ipfs-cmds library handles input file filtering before the directory
tree is passed to kubo. removed unused Import.UnixFSSymlinkMode config
option that was defined but never actually read by the CLI.

also:
- wire --trickle to Import.UnixFSDAGLayout config default
- update go-ipfs-cmds to v0.15.1-0.20260117043932-17687e216294
- add SYMLINK HANDLING section to ipfs add help text
- add CLI tests for all three flags

ref: ipfs/specs#499

* test(add): add CID profile tests and wire SizeEstimationMode

add comprehensive test suite for UnixFS CID determinism per IPIP-499:
- verify exact HAMT threshold boundary for both estimation modes:
  - v0-2015 (links): sum(name_len + cid_len) == 262144
  - v1-2025 (block): serialized block size == 262144
- verify HAMT triggers at threshold + 1 byte for both profiles
- add all deterministic CIDs for cross-implementation testing

also wires SizeEstimationMode through CLI/API, allowing
Import.UnixFSHAMTSizeEstimation config to take effect.

bumps boxo to ipfs/boxo@6707376 which aligns HAMT threshold with
JS implementation (uses > instead of >=), fixing CID determinism
at the exact 256 KiB boundary.

* feat(add): --dereference-symlinks now resolves all symlinks

Previously, resolving symlinks required two flags:
- --dereference-args: resolved symlinks passed as CLI arguments
- --dereference-symlinks: resolved symlinks inside directories

Now --dereference-symlinks handles both cases. Users only need one flag
to fully dereference symlinks when adding files to IPFS.

The deprecated --dereference-args still works for backwards compatibility
but is no longer necessary.

* chore: update boxo and improve changelog

- update boxo to ebdaf07c (nil filter fix, thread-safety docs)
- simplify changelog for IPIP-499 section
- shorten test names, move context to comments

* chore: update boxo to 5cf22196

* chore: apply suggestions from code review

Co-authored-by: Andrew Gillis <11790789+gammazero@users.noreply.github.com>

* test(add): verify balanced DAG layout produces uniform leaf depth

add test that confirms kubo uses balanced layout (all leaves at same
depth) rather than balanced-packed (varying depths). creates 45MiB file
to trigger multi-level DAG and walks it to verify leaf depth uniformity.

includes trickle subtest to validate test logic can detect varying depths.

supports CAR export via DAG_LAYOUT_CAR_OUTPUT env var for test vectors.

* chore(deps): update boxo to 6141039ad8ef

switches to ipfs/boxo@6141039

changes since 5cf22196ad0b:
- refactor(unixfs): use arithmetic for exact block size calculation
- refactor(unixfs): unify size tracking and make SizeEstimationMode immutable
- feat(unixfs): optimize SizeEstimationBlock and add mode/mtime tests

also clarifies that directory sharding globals affect both `ipfs add` and MFS.

* test(cli): improve HAMT threshold tests with exact +1 byte verification

- add UnixFSDataType() helper to directly check UnixFS type via protobuf
- refactor threshold tests to use exact +1 byte calculations instead of +1 file
- verify directory type directly (ft.TDirectory vs ft.THAMTShard) instead of
  inferring from link count
- clean up helper function signatures by removing unused cidLength parameter

* test(cli): consolidate profile tests into cid_profiles_test.go

remove duplicate profile threshold tests from add_test.go since they
are fully covered by the data-driven tests in cid_profiles_test.go.

changes:
- improve test names to describe what threshold is being tested
- add inline documentation explaining each test's purpose
- add byte-precise helper IPFSAddDeterministicBytes for threshold tests
- remove ~200 lines of duplicated test code from add_test.go
- keep non-profile tests (pinning, symlinks, hidden files) in add_test.go

* chore: update to rebased boxo and go-ipfs-cmds PRs

* docs: add HAMT threshold fix details to changelog

* feat(mfs): use Import config for CID version and hash function

make MFS commands (files cp, files write, files mkdir, files chcid)
respect Import.CidVersion and Import.HashFunction config settings
when CLI options are not explicitly provided.

also add tests for:
- files write respects Import.UnixFSRawLeaves=true
- single-block file: files write produces same CID as ipfs add
- updated comments clarifying CID parity with ipfs add

* feat(files): wire Import.UnixFSChunker and UnixFSDirectoryMaxLinks to MFS

`ipfs files` commands now respect these Import.* config options:
- UnixFSChunker: configures chunk size for `files write`
- UnixFSDirectoryMaxLinks: triggers HAMT sharding in `files mkdir`
- UnixFSHAMTDirectorySizeEstimation: controls size estimation mode

previously, MFS used hardcoded defaults ignoring user config.

changes:
- config/import.go: add UnixFSSplitterFunc() returning chunk.SplitterGen
- core/node/core.go: pass chunker, maxLinks, sizeEstimationMode to
  mfs.NewRoot() via new boxo RootOption API
- core/commands/files.go: pass maxLinks and sizeEstimationMode to
  mfs.Mkdir() and ensureContainingDirectoryExists(); document that
  UnixFSFileMaxLinks doesn't apply to files write (trickle DAG limitation)
- test/cli/files_test.go: add tests for UnixFSDirectoryMaxLinks and
  UnixFSChunker, including CID parity test with `ipfs add --trickle`

related: boxo@54e044f1b265

* feat(files): wire Import.UnixFSHAMTDirectoryMaxFanout and UnixFSHAMTDirectorySizeThreshold

wire remaining HAMT config options to MFS root:
- Import.UnixFSHAMTDirectoryMaxFanout via mfs.WithMaxHAMTFanout
- Import.UnixFSHAMTDirectorySizeThreshold via mfs.WithHAMTShardingSize

add CLI tests:
- files mkdir respects Import.UnixFSHAMTDirectoryMaxFanout
- files mkdir respects Import.UnixFSHAMTDirectorySizeThreshold
- config change takes effect after daemon restart

add UnixFSHAMTFanout() helper to test harness

update boxo to ac97424d99ab90e097fc7c36f285988b596b6f05

* fix(mfs): single-block files in CIDv1 dirs now produce raw CIDs

problem: `ipfs files write` in CIDv1 directories wrapped single-block
files in dag-pb even when raw-leaves was enabled, producing different
CIDs than `ipfs add --raw-leaves` for the same content.

fix: boxo now collapses single-block ProtoNode wrappers (with no
metadata) to RawNode in DagModifier.GetNode(). files with mtime/mode
stay as dag-pb since raw blocks cannot store UnixFS metadata.

also fixes sparse file writes where writing past EOF would lose data
because expandSparse didn't update the internal node pointer.

updates boxo to v0.36.1-0.20260203003133-7884ae23aaff
updates t0250-files-api.sh test hashes to match new behavior

* chore(test): use Go 1.22+ range-over-int syntax

* chore: update boxo to c6829fe26860

- fix typo in files write help text
- update boxo with CI fixes (gofumpt, race condition in test)

* chore: update go-ipfs-cmds to 192ec9d15c1f

includes binary content types fix: gzip, zip, vnd.ipld.car, vnd.ipld.raw,
vnd.ipfs.ipns-record

* chore: update boxo to 0a22cde9225c

includes refactor of maxLinks check in addLinkChild (review feedback).

* ci: fix helia-interop and improve caching

skip '@helia/mfs - should have the same CID after creating a file' test
until helia implements IPIP-499 (tracking: ipfs/helia#941)

the test fails because kubo now collapses single-block files to raw CIDs
while helia explicitly uses reduceSingleLeafToSelf: false

changes:
- run aegir directly instead of helia-interop binary (binary ignores --grep flags)
- cache node_modules keyed by @helia/interop version from npm registry
- skip npm install on cache hit (matches ipfs-webui caching pattern)

* chore: update boxo to 1e30b954

includes latest upstream changes from boxo main

* chore: update go-ipfs-cmds to 1b2a641ed6f6

* chore: update boxo to f188f79fd412

switches to boxo@main after merging ipfs/boxo#1088

* chore: update go-ipfs-cmds to af9bcbaf5709

switches to go-ipfs-cmds@master after merging ipfs/go-ipfs-cmds#315

---------

Co-authored-by: Andrew Gillis <11790789+gammazero@users.noreply.github.com>