test(mcp): find-opportunities.ts's searchQuery + goal-spec + token-fallback paths are untested (79.34% branch coverage)

[JSONbored]

Context

src/mcp/find-opportunities.ts's runFindOpportunities (the hosted loopover_find_opportunities
MCP tool, #2308) has several real, reachable branches that test/unit/find-opportunities.test.ts
never exercises. A local unsharded npm run test:coverage run shows the file at 79.34% branch
coverage (96/121) — the lowest of any src/mcp/** file.

Confirmed-untested paths (verified by reading both the source and the full existing test file, which
only calls runFindOpportunities with targets, never searchQuery):

• The entire parsed.searchQuery branch of runFindOpportunities (lines 232-235: calling
  searchCandidateIssuesWithSummary instead of fetchCandidateIssuesWithSummary) and the
  post-search canAccessRepo re-filter (lines 251-257) are never taken — every existing test passes
  targets, never searchQuery.
• buildGoalSpecsByRepo (lines 132-151) is never called with a real goalSpec.lane or
  goalSpec.languages — no test asserts that a supplied lane narrows preferredLabels or that
  languages becomes wantedPaths globs, and the !lane && languages.length === 0 early-return
  (undefined) vs. the populated-spec path are both unverified.
• appliedLane / appliedMinRankScore / warnings inclusion in the final result (lines 269-276):
  no test asserts these optional fields actually appear in result when a lane/minRankScore/warning
  is present, nor that they're omitted when absent.
• resolveDiscoveryGithubToken's installation-token fallback loop (lines 178-198): when
  env.GITHUB_PUBLIC_TOKEN is unset, the loop over reposByFullName.values() — skipping a repo with
  no installationId (line 190's continue), calling createInstallationToken for one that has it,
  and the try/catch swallowing a createInstallationToken failure to try the next repo — has zero
  test coverage. Every existing test either sets GITHUB_PUBLIC_TOKEN or expects
  github_token_unavailable.
• validated.ok === false at the top of runFindOpportunities (line 208): the shared
  validateFindOpportunitiesInput rejection paths are tested directly, but not through
  runFindOpportunities itself.

Requirements

Add test cases to test/unit/find-opportunities.test.ts:

1. A searchQuery-only call (no targets) that stubs searchCandidateIssuesWithSummary (via the
   same fetch stub pattern the existing tests use for fetchCandidateIssuesWithSummary) and asserts
   result.status === "ok" with issues from the search path; combine with a canAccessRepo that
   rejects one returned repo, asserting it's filtered out post-search.
2. A goalSpec.lane + goalSpec.languages call asserting appliedLane is present in the result and
   that ranking behavior differs from an unscoped call (or at minimum that buildGoalSpecsByRepo's
   output shape reaches the ranker — e.g. via a spy/mock if rankCandidateIssuesWithSummary is
   swappable, otherwise assert on appliedLane/appliedMinRankScore presence).
3. A call with goalSpec.minRankScore above 0 asserting appliedMinRankScore is present in the
   result, and a call with neither lane nor minRankScore asserting both are omitted.
4. resolveDiscoveryGithubToken (may need an internal export, or exercise via runFindOpportunities
   with GITHUB_PUBLIC_TOKEN unset): one target with no stored installation (skipped), one target
   whose createInstallationToken call is stubbed to throw (falls through to the next repo), and one
   whose token resolves successfully.
5. A directly-invalid runFindOpportunities input (e.g. no targets and no searchQuery) asserting
   status: "invalid_request" end-to-end, not just via validateFindOpportunitiesInput in isolation.

Deliverables

• New it(...) blocks in test/unit/find-opportunities.test.ts covering the five requirement
  groups above.

Test Coverage Requirements

src/mcp/find-opportunities.ts is scored by the 99%+ codecov/patch gate on any future touching PR.
This issue should bring the file from 79.34% to at or near 100% branch coverage.

Expected Outcome

runFindOpportunities's searchQuery path, goal-spec application, applied-field reporting, and
installation-token fallback are all provably correct, not just the targets + GITHUB_PUBLIC_TOKEN
happy path currently tested.

Links & Resources

• src/mcp/find-opportunities.ts
• test/unit/find-opportunities.test.ts (file to extend)
• Related: test/unit/mcp-find-opportunities.test.ts, test/unit/mcp-cli-find-opportunities.test.ts
  (MCP-tool-wrapper-level tests — check these don't already cover the search-query path before
  duplicating; if they do, port the missing scenarios down to the unit-level test instead)

[linear-code]

JSO-4034