uw-resolve P0.5: freeze reasons, named layers, excluded, aliases

[s243a]

Holds get reasons; mining-notes adoptions land. Branches from grok/pkg-resolver. Spec from PACKAGE_MANAGER_LOGIC_PROPOSAL.md §2e (graduated freeze) / §2f (named layers) and PKG_MINING_NOTES.md top-10. Design docs are imported unmodified. Edit scope is examples/pkg_resolver/ plus those two reference docs.

Catalog shape (P0 catalog/6 still accepted)

Bare Name-Ver = blanket. Extras via catalog/9:

catalog(Packages, Depends, Conflicts, Base, Installed, Requested,
        Layers, Excluded, Aliases)

Combined example (reasons + a second loaded layer + excluded + alias):

catalog(
  [package(lib,v(1,0,0)), package(lib,v(2,0,0)),
   package(app,v(1,0,0)), package(gcc,v(1,0,0)),
   package(rxvt,v(1,0,0)), package(bad,v(1,0,0))],
  [depends(app,v(1,0,0),lib,any), depends(lib,v(1,0,0),gcc,any)],
  [],
  [base(lib-v(1,0,0), abi_anchor), base(app-v(1,0,0), footprint)],
  [app-v(1,0,0), lib-v(1,0,0)],
  [app],
  [layer(devx, [gcc-v(1,0,0)])],
  [bad],
  [alias(urxvt, rxvt)]).

safe_upgrade verdicts: safe(cost(Reason)) (footprint/blanket/layer_shadow), coordinated(Set) (abi_anchor), unsafe(modified), no_candidate. upgrade_set is the reverse-dep closure over BASE holds whose constraint breaks at NewVer; a tolerant dep stays out; a member with no repair binds blocked/3. Exclusion filters candidate generation only — never removal_orphans. Aliases rewrite at the request edge; catalog names stay canonical.

New scenarios (16; all 22 P0 tests unchanged)

safe_upgrade footprint / blanket / layer_shadow / modified / no_candidate / coordinated; upgrade_set minimality (tool with any stays out) + blocked/3; freeze_audit over_frozen + suggest(abi_anchor); named layer satisfies a dep + layer_closure omits loaded; excluded never selected / excluded does not block removal; dependents + dependents_installed; alias at the request edge.

Gates (measured)

Gate	Result
swipl … test_resolver.pl	38/38 (22 P0 + 16 P0.5)
run_corpus_wamjs.sh	39/39 matched SWI
run_differential.sh	2400 cases, 0 divergences, 0 crashes — swi 1.427s, wamjs 5.370s (seed 0xa5b6c7d8, all 10 queries)
tests/test_wam_javascript_lowered.pl	18 tests, exit 0
tests/test_wam_javascript_builtins.pl	13 tests, exit 0
tests/test_wam_javascript_fact_sources.pl	8 tests, exit 0
CONFORMANCE_TARGETS=javascript	exit 0 (no javascript adapter registered)
cli_args corpus	17/17
cli_args differential	5067 / 0 / 0 (oracle 0.055s, wamjs 2.190s)

No JS WAM runtime/emitter/target/template edits. No runtime bug exposed; no workaround.

Residuals (still deferred)

P2 GP-LMDB catalog backend, Provides/virtual, epoch/tilde, CLI, write paths, per-file layer modeling.