Activate Bun publish corpus and registry lifecycle semantics

Parent: #66

Tracks the untouched Bun publish corpus at cli/install/bun-publish.test.ts.

Scope

• lower standalone named exports without changing the upstream corpus source
• model Verdaccio package storage, auth/OTP/notice exchange, CI user agents, README metadata, tags, access, dry-run, private packages, and republish behavior
• publish from workspaces and tarballs
• install published packages, dependencies, peers, optional dependencies, and recursive directory bins
• preserve lifecycle ordering and npm lifecycle environment output
• add an authoritative exact-corpus regression

Acceptance

• copied source remains byte-identical to ~/Code/bun
• bun-publish.test.ts reports 34 passed, 0 failed, 0 unsupported, 0 TODO
• adjacent install and pack corpus remains green
• full home_test gate passes
• landed commit and final evidence posted here and in #66

Landed in eff87588c (feat: activate bun publish compatibility).

Native home publish activation remains tracked separately in #186 because Bun's copied PackCommand still uses pre–Zig 0.17 filesystem APIs; this issue does not claim that unfinished native path.

Completed in eff87588c (feat: activate bun publish compatibility), pushed directly to main with Chris Breuer as the sole author and committer.

Verification:

• exact upstream cli/install/bun-publish.test.ts: 34 passed / 0 failed / 0 unsupported / 0 TODO
• source SHA-256: d797f1ad02a4bbce54052d940c6c49e555bd08596e79e244d08eb16e6c266544, byte-identical to ~/Code/bun/test/cli/install/bun-publish.test.ts
• adjacent bun-pack.test.ts: 71/71
• adjacent bun-install.test.ts: 184 passed, with the same 2 upstream TODOs
• adjacent bun-pm-pkg.test.ts: 73 passed, with the same 1 upstream TODO
• bun-remove.test.ts: 5/5
• bun-run-bunfig.test.ts: 28/28
• bun-run-dir.test.ts: 3/3
• issue 24314 pack lifecycle regression: 2/2
• debug build: exit 0
• full home_test gate: exit 0 after fixing specialized/general pack dispatch ownership
• zig fmt --check and git diff --check: pass

The sorted untouched corpus ratchet is green through index 165. The next boundary is index 166, cli/install/bun-run.test.ts, whose single failure is stdin execution: console.log('hello') | bun run - should print hello.

Native publish/pack command activation remains open in #186.