Expand README and split into English/Chinese editions

[oratis]

User outcome

A reader landing on the repository can now understand what Andromeda is, run it, and call
its shipped interfaces without reading source or docs/ first. English becomes the primary
README.md; the Chinese edition moves to README.zh-CN.md, cross-linked from both. The two
files keep 1:1 section parity (18 ## sections each) so they can be reviewed and updated
together.

What was missing

The previous README covered status, goals, and the crate table, but left every shipped
interface undocumented — no CLI reference, no HTTP API reference, no risk/capability model,
no OS build or acceptance flow. It was also Chinese-only with a ~15-line English summary,
putting non-Chinese readers behind a translation step on the front page.

New reference material

All of it verified against the source, not written from memory:

• CLI — all 8 subcommands, the global --state-dir, --isolation resolution semantics,
  and the 0/2/3 exit codes of hardware check.
• HTTP API — all 7 endpoints, all 7 error codes, the deny_unknown_fields rejection
  behavior, and the exact scope of the Host-header DNS-rebinding defense.
• Core model — risk levels and isolation floors, per-ActionKind risk floors and target
  semantics, the four capability resource kinds, the policy decision order, and a Mermaid
  state-machine diagram with its invariants.
• Durability — compaction write ordering, the crash-safety guarantee, and the
  10,000-action plan limit.
• OS image — build, install E2E, hardware matrix, and GCP nested-KVM flows, with the
  destructive CI boot entry raised into a > [!WARNING] alert.
• CI — what each of the two workflows actually gates on.

Real output, not fabricated samples

The JSON blocks are captured from actual runs of hardware probe, hardware check,
task create-inspection, and task evaluate against a locally built binary. Paths in the
task samples are shortened for readability; field structure and values are unmodified. The
hardware check sample happens to show effective_tier: blocked on an Apple silicon host,
which doubles as a concrete demonstration that probing is not support.

Boundary claims preserved

This repository's documentation is deliberately conservative, and none of that was diluted for
readability. Carried through verbatim in both editions: Ready is not authorization to
execute; --isolation is not a sandbox proof; Host validation is not authentication; probing
is not support; the outstanding one-pass GCP re-run; and the explicit not-implemented list
(executor, credential broker, verifier, signed policy bundle, remote auth). Both ISO SHA-256
values are kept in full — I had truncated them at one point and restored them, since a
truncated checksum is not verification data.

Validation

• All 41 repo-relative links in both files resolve to existing paths (scripted check).
• Section parity confirmed: 18 ## headings in each file, same order.
• No code or config touched — the diff is README.md and the new README.zh-CN.md only.

🤖 Generated with Claude Code