feat(insurance): list vendor line items for explicit Archera comparison filters #2266

Agent/session: cc-crossrepo-inventory, coordinated with resume-cc-audit.

Use case: after #2265, archera-comparison accepts --line-item-ids, but the CLI cannot list the vendor line-item UUIDs to pass to that flag. At main 021f162, only the comparison command is registered. These are Archera IDs; platform recommendation IDs are not portable substitutes.

Proposed focused delivery: an explicit read-only archera-line-items command, table/JSON output, existing environment-only key and org/plan configuration, and bounded local result pages with complete-fetch-before-output semantics. It uses the existing shared insurance.Client.LineItems operation rather than reimplementing pagination or matching. Return vendor line/offer IDs, selection and the limited offer dimensions needed to choose comparison filters. Do not return raw cloud account identifiers, organization IDs, raw responses or credentials. Clearly label local result pagination versus the internal vendor pagination, and retain disclosures and unknown currency/quote limits.

Prerequisite: pin only github.com/LeanerCloud/cloud-commitments-go/pkg to the earliest already published LineItems version v0.0.0-20261016175124-570d168c6bc7. Keep provider pins unchanged and review module/sum changes. The old CLI pin is 9b35837e78d1. The newer comparison decoder requires selected_amount, so audit all fixtures and retain complete existing comparison coverage. Its normal wire fixture already includes this field on every offer.

The listing must emit exact decimal strings, not floats or fractions. Existing archeraMoney falls back to a fraction past 100 decimal places although the shared decoder accepts 1e-101. Review the minimal bounded precision correction with an actual real-client decimal regression; do not silently round or copy another decimal algorithm.

Proof: actual root command -> real insurance.Client -> intercepted fixed-origin transport, complete 101-row/two-vendor-page result, local-page boundaries and ID reuse in archera-comparison; late-page error yields no partial stdout. Cover invalid bounds/config/UUIDs before requests, missing or changed pagination metadata, duplicate IDs, cancellation, cumulative size limit, 429/Retry-After without retries, redirects, exact long decimals/zero/null dimensions, hostile text and captured output/log redaction. Help and unrelated commands must send no vendor request. Update command help and docs in the same completion gate.

No live vendor calls, package installation, purchases, binding, implicit comparisons or platform recommendation matcher. #798 in cloud-commitments-platform remains a separately human-authorized recorded-response blocker; synthetic consumer evidence cannot close it. Related cross-repo tracking: platform#786/#799 and the paired MCP listing issue.

Duplicate searches across all states for archera, line items and line-item found only completed comparison/filter issues (#2156/#2264), not this listing feature. No open CLI PR exists at inspection. This issue tracks proposed work pending independent plan review; no code/worktree has been created.