test(mcp): cover bazaar_search, ListTools, and unknown-tool paths - #524

The payment ledger registered mcp_payment_* counters on the shared registry,
but the MCP process serves no listener that reads it, so the spend of an agent
was still only recoverable from the audit file. Serve GET /metrics from the MCP
HTTP transport, on the same bearer token as paid_call, and refuse to start when
MCP_HTTP_PATH would put the MCP handshake on that path.

The network label was always unknown in the shipped server because run.ts only
passed the host allow-list. Default the network domain to the two networks the
signer is configured for, overridable with MCP_METRIC_NETWORKS, so a series per
network exists without opening the label to whatever a seller echoes.

…ibraries throw

The original four fixtures were duck-typed stubs: bare Error strings and
plain-object responses. Rewire them on the actual chain: the @x402/stellar
simulation guard wrapped by @x402/fetch's payment-payload frame, and real
Response objects for the 402 and success paths. Drop the hand-rolled
handler captures for the file's createHarness.

… surface

The merge of main into this branch interleaved two independent rewrites of
src/mcp/server.ts (HTTP transport + spend ledger vs. allow-list + price tool +
SSRF + zod), leaving ~170 parse errors that broke `tsc --noEmit`. Reconstructed
the merge properly: union error codes with main's Divinity-Labs#480 structured classifier,
one coherent McpServerConfig/constructor, the paid_call path keeps our
fail-closed ledger and budget ordering around main's allow-list gate and
timeout, and examples/run.ts wires both features.

tests/mcp.test.ts: deduplicated auto-merged import blocks, pointed the harness
at a public DNS answer so main's SSRF guard lets discovery through, and updated
assertions to the merged error reasons. tests/mcp-http.test.ts: allow-list the
hosts its paid calls use and expect the upstream timeout signal.

Verified against this exact tree: tsc --noEmit EXIT=0 and full vitest suite
990 passed | 1 skipped.

The merge of main into this branch was resolved by keeping both sides of
every conflict, so server.ts held two constructors, two CallTool handlers
and returns stacked behind returns — 29 parse errors, and the typecheck
never reached the semantic error the same resolution left in codes.ts
(ERR_BUDGET_EXCEEDED twice).

Resolve each conflict on intent instead: the HTTP transport builds one
protocol server per request, so main's resources/list and resources/read
handlers register on the passed-in target rather than this.server;
bazaar_search and paid_call keep main's paging and byte caps, with the
payment ledger still recording every attempt that reached the transport;
payment_budget reports recordedSpend inside the bounded result.

The two branch-side discovery tests asserted the pre-paging URLs, so they
now expect the limit and offset main's resolvePage adds.

…kfile

The lockfile was last regenerated on Windows, so every optional dependency
for another platform lost its package entry: 25 @esbuild/*, 16
@rolldown/binding-*, 10 lightningcss-*, 5 @msgpackr-extract/*, fsevents,
and the 6 @emnapi/@napi-rs/@tybys wasm helpers those pull in. `npm ci`
still succeeds — it installs exactly what the lock names — so the runner
gets rolldown with no native binding and vitest 4 dies before collecting a
single test: "Cannot find module '@rolldown/binding-linux-x64-gnu'".

main is red at this same step for the same reason, so every branch merged
from it inherits a failing `npm test` that no change to src/ or tests/ can
clear.

Restore all 63 entries from the pre-merge lockfile, whose versions match
what esbuild, rolldown, lightningcss, msgpackr-extract and prisma still ask
for here, and check each integrity hash and tarball URL against
registry.npmjs.org. Nothing else moves: the 483 entries already in the
lock are byte-identical, and `npm ci --dry-run` resolves on linux-x64
(picking up @rolldown/binding-linux-x64-gnu) and on win32-x64.

main's drift guard now scans examples/ and scripts/ as well as src/
(Divinity-Labs#413), and examples/mcp-server/run.ts reads MCP_METRIC_NETWORKS, so the
merged tree fails the guard on a variable this branch introduced.

It was commented out on purpose: an empty value reports every network as
`unknown`. Spell out the default the code already falls back to
(DEFAULT_MCP_METRIC_NETWORKS) instead, which documents the variable
without changing what an operator copying this file gets.