Background

The recommendations table at frontend/src/recommendations.ts:1147-1158 currently renders these per-rec columns:

Provider · Account · Service · ResourceType · Region · Count · Term · Monthly savings · Upfront cost

Each rec carries a single payment value (all-upfront / partial-upfront / no-upfront) and a corresponding (upfront_cost, monthly_cost) pair on RecommendationRecord (internal/config/types.go):

UpfrontCost  float64 `json:"upfront_cost"`
MonthlyCost  float64 `json:"monthly_cost"`
Savings      float64 `json:"savings"`        // monthly savings vs on-demand

After PR #195 (issue #188) the user can now choose between all three payment variants of the same (service, region, SKU, term) cell. But the table only shows upfront_cost — so for a no-upfront rec the row reads "$0 upfront" with no indication of what the recurring cost actually is, and for partial-upfront the row is missing half its cost picture. The user has to do mental math against the savings column to compare options.

What needs to happen

Add a "Monthly cost" column rendering formatCurrency(rec.monthly_cost) next to the existing Upfront column. After this PR:

• no-upfront rec: Upfront = $0, Monthly = $X, Savings = $Y (whole story visible)
• partial-upfront rec: Upfront = $X, Monthly = $Y, Savings = $Z (whole story visible)
• all-upfront rec: Upfront = $X, Monthly = $0, Savings = $Y (whole story visible)

Hooks the existing column infrastructure already has: monthly_cost is a known field, just not in the rendered list.

Sketch

• recommendations.ts:
  • Add a <th> for "Monthly cost" between "Upfront cost" (rendered after Savings today) and the action column. Or put it next to Upfront — designer's call.
  • Add a <td>${formatCurrency(rec.monthly_cost)}</td> in the row template.
  • Wire into the per-column sort + filter helpers that already exist for upfront_cost (SORTABLE_NUMERIC_COLUMNS, the popover registry, the friendly-name table, etc.). Mirror the upfront-cost shape.
• Frontend tests: a row-render test asserting the Monthly column appears for all three payment variants with the expected value.

Acceptance

• The recommendations table shows both Upfront and Monthly cost per rec.
• Users can sort and filter by the new column the same way they can by Upfront.
• Existing tests still pass; new tests pin the rendering for each payment variant.

References

• PR fix(aws): fetch every Cost Explorer (term, payment) combo (#188) #195 (the term × payment fan-out that made this gap visible)
• Issue fix(recommendations): AWS 1-year-term recs missing — only 3yr recs render when both exist #188 (the original term-only bug)
• frontend/src/recommendations.ts:1147-1158 (the row template)
• frontend/src/recommendations.ts:130-160 (the sort/column registries)
• internal/config/types.go::RecommendationRecord (the MonthlyCost field already on the wire)