Simplify: remove pass-through layers, dead code, and copy-pasted helpers

[Soph]

Summary

A de-slop pass over the whole repo: −840 net lines with no feature or public-API change. Each commit is standalone and could be split into its own PR for review.

1. Fold internalbridge into the root package — internal/internalbridge was a pure pass-through layer: it mirrored the public request types field-for-field, wrapped syncer.Config in an opaque struct, and forwarded Probe/Run verbatim. The public result types are now defined directly in the root package (same fields, same JSON tags), which also makes their godoc visible on pkg.go.dev and exports SideBytes (previously reachable through Stats.Sides but not nameable by callers).
2. Delete dead code kept alive only by its own tests — four unreferenced planner helpers, the parallel PushPlan/ToPushCommands conversion path, FetchCommitGraph (superseded by FetchCommitParents, whose capability guards are now tested directly), progressWriter, HashHex, the FetchFeatures struct, and the unreachable authAdapter in convert-sha256.
3. Share copy-pasted helpers — closeOnceReadCloser existed verbatim in three strategy packages (now gitproto.CloseOnce, with the unit test it never had); the byte formatter existed three times (now gitproto.HumanBytes); the plan-classification switch existed twice in the syncer (now classifyPlans); auth.Method duplicated gitproto.AuthMethod.
4. Clean up CLI flag plumbing — convert-sha256 reuses addSourceAuth (including its secret-leak protection), shared parseMappings, collapsed the protocolModeFlag type ladder, versioninfo.String(), slices.Compact.
5. Drop redundant protocol/mode defaulting — syncer.newSession already normalizes empty protocol → auto and empty mode → sync; both clients repeated that defaulting.

Review

Multi-angle review (line-by-line, removed-behavior audit, cross-file trace, reuse/altitude) ran on the full diff; correctness angles came back clean and the two actionable notes were fixed in the last commit. Two trade-offs were considered and accepted:

• syncerEndpoint/validationMappings are now duplicated between the stable and unstable clients (~24 lines) — the only shared home would be a bridge-style package, i.e. the indirection this PR removes.
• HumanBytes lives in gitproto (the one package all consumers, including gitproto itself, already import); the pack-encode ticker now formats like the rest of the progress output.

Testing

• go test -race ./... green (CI parity)
• golangci-lint run — 0 issues; gofmt -s clean
• CLI smoke-checked: version, --version, --help for sync/convert-sha256, --mode validation error path

🤖 Generated with Claude Code

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Note

Medium Risk
Large refactor across sync orchestration, gitproto fetch/push, and strategy relay paths; behavior should be unchanged but the blast radius warrants careful review and existing test coverage.

Overview
This PR is a de-slop refactor (~840 net lines removed) with no intended feature or public API behavior change.

Public client path: internal/internalbridge is deleted. The root gitsync client now builds syncer.Config directly and maps syncer results via fromProbeResult / fromSyncResult in results.go. Result types (RefResult, ProbeResult, SyncResult, etc.) live in the root package instead of being re-exported through the bridge. The unstable client follows the same pattern (direct syncer.Endpoint construction, no bridge).

Shared internals: Pack reader helpers move to gitproto (CloseOnce, LimitPackReader, exported HumanBytes). Relay strategies and sync progress/batching use those instead of local copies. auth.Method is aliased to gitproto.AuthMethod so convert-sha256 no longer needs an authAdapter. Sync/replicate planning share new classifyPlans in the syncer.

Removed dead paths: Unused planner/gitproto/convert helpers (PushPlan/ToPushCommands, FetchCommitGraph, FetchFeatures, HashHex, progressWriter, etc.) and duplicate tests.

CLI: Shared parseMappings, addSourceAuth on convert-sha256, versioninfo.String() for version output, simpler protocol/mode flag types, slices.Compact in git-sync-bench.

^{Reviewed by Cursor Bugbot for commit d715649. Configure here.}