docs(fork-c/S0): setup contract — byte-baseline + commit-discipline, E6b disposition + two-corpus partition, A–E6 reuse/delete ledger

S0 of the ratified Fork C plan (zero-legacy name-resolution redesign, S0→S6).
Pure setup/documentation: NO production code change, NO behavior change.
Single-author output byte-identical to wt-stdlib-base by construction.

Deliverables under docs/fork-c/ (docs/, not current/, because current/ is
gitignored and the contract must be committed):

S0.1 — byte-baseline + commit-discipline: the committed examples/expected/*
snapshots are the single-author byte-identity reference; the zero-diff repro is
`zig build && zig build test && bash tests/run_examples.sh`. Resolver-target set
explicitly excluded + listed. Commit-classification rule: mirror | consumer-cutover | deletion.

S0.2 — E6b disposition + two-corpus partition: transitional E6b src NOT merged
(grep-clean: no resolveRegistrationSigTypeInSource / sig_registration_mode /
e6br_gate.test.zig on baseline). Harvested 0811–0829 trees + goldens (never the
src), empirically partitioned by running each through the base compiler vs the
E6b target:
  - baseline-green (mirror-equivalence): 0795–0798 (merged) + 0823, 0828 — given
    examples/expected/ markers, locked into the S0 baseline.
  - resolver-target (known-wrong old behavior): 0811–0822, 0824–0827, 0829 + the
    re-filed E6BR-5 nested-pattern regression — a listed xfail harness under
    tests/resolver-target/ (manifest + TARGET goldens, NO active marker), flips
    active+green at S3.9. 0811/0829 noted as old-selector-wrong on the E6b-unmerged
    base; E6BR-5 subsumed by the whole-AST resolver, NOT an E6b attempt-6.

S0.3 — A–E6 reuse/delete ledger: every load-bearing A–E6 artifact mapped REUSED
(Fork C home) or DELETED/TRANSITIONAL (S3/S6 phase); E6c/d/e dropped, F/H/I/K
absorbed/superseded.

Gate over the baseline-green corpus: zig build + zig build test (LSP corpus sweep
574 files, no crash) + bash tests/run_examples.sh (540 passed, 0 failed) all exit 0.

tests/resolver-target/README.md

@@ -0,0 +1,49 @@
+# Resolver-target corpus (Fork C)
+
+The second of the two Fork C resolver-acceptance corpora. See the full contract in
+`../../docs/fork-c/S0.2-e6b-disposition-and-two-corpus-partition.md`.
+
+- **What it is:** harvested E6b semantics goldens (+ the re-filed E6BR-5 regression)
+  that encode the **TARGET** behavior of the Fork C resolver for cases where the
+  **old name-selector is known-wrong on `wt-stdlib-base`** (E6b unmerged) — it
+  silently resolves a global last-wins author / under-diagnoses / picks the wrong
+  author. On this base the old selector is **not a valid oracle**, so these are NOT
+  baseline-green.
+- **Why separate:** the S2 assert-only mirror proves `resolver == old-selector` over
+  the **baseline-green corpus ONLY**. Asserting that over these cases would force the
+  new resolver to reproduce the old bug. So they live here, inactive, with NO active
+  `examples/expected/` marker — `tests/run_examples.sh` does not run them.
+- **Never silently dropped:** every case is enumerated in `manifest.md`, its TARGET
+  golden is recorded in `expected/`, and `run_resolver_target.sh` asserts each case
+  currently FAILS to match its target (xfail). If any case unexpectedly MATCHES on
+  the base, the runner flags it `LEAKED` — it is actually baseline-green and must be
+  re-classified (moved to `examples/expected/`), never left here.
+- **Flip at S3.9:** the Fork C resolver makes these pass; each golden moves to
+  `examples/expected/<name>.{exit,stdout,stderr}` and this harness goes empty.
+
+## Layout
+
+```
+manifest.md                 enumerated list of all 18 cases (class / base-now / target / note)
+expected/<name>.exit        TARGET exit (08xx: exact E6b bytes; e6br5: spec)
+expected/<name>.stdout      TARGET stdout (08xx only — exact E6b bytes)
+expected/<name>.stderr      TARGET stderr (08xx only — exact E6b bytes)
+expected/e6br5-*.target.md  E6BR-5 spec target (exact bytes finalized at S3.9)
+cases/e6br5-*.sx + dir/     E6BR-5 authored reproducer (self-contained)
+run_resolver_target.sh      xfail runner (NOT part of the baseline gate)
+```
+
+The 08xx **source trees** live under `examples/` (harvested as authored, so their
+`#import` paths resolve exactly as their baseline-green siblings do) but carry **no**
+`examples/expected/` marker, so they are inert to `run_examples.sh`. Only their
+goldens live here. The E6BR-5 reproducer lives entirely under `cases/` (it is
+self-contained — `modules/std.sx` resolves via the `library/` search path).
+
+## Run
+
+```
+zig build                                 # build the compiler first
+bash tests/resolver-target/run_resolver_target.sh
+```
+
+Expected today (S0): all 18 cases print `xfail`, `0 leaked`, exit 0.