fix(i18n): drop orphan TerminalPane.minimumContrast entries that broke main

#18126 added a `auto.components.settings.TerminalPane.minimumContrast` block
to en.json alongside the `settings.contrast.*` keys the shipped
TerminalContrastSetting component actually reads. Nothing references the
TerminalPane block: zero call sites, zero tests, zero other locales, and no
dynamic key builder under `auto.components.settings.*` can produce it (the
only template-literal builder in that namespace is a test consumer that reads
paths from the catalog, not one that constructs them).

An unreferenced entry is treated as runtime-required by
generate-runtime-required-english-catalog (possible dynamic key), so the
seven orphans made `verify:localization-runtime-catalog` demand they ship in
en-runtime-required.json. #18126 never regenerated it, and its own
static-analysis gate was cancelled rather than run, so main has failed that
step for every PR since 53852c9 merged.

Delete the orphans rather than regenerate the catalog around them:
regenerating would enshrine seven keys nothing reads.

src/renderer/src/i18n/locales/en.json

@@ -8627,15 +8627,6 @@
             "fastDescription": "Extra multiplier while scrolling with a modifier key.",
             "tui": "TUI",
             "tuiDescription": "Discrete wheel reports for full-screen terminal apps."
-          },
-          "minimumContrast": {
-            "title": "Minimum Contrast Ratio",
-            "description": "Lifts terminal foreground colors that sit too close to the background. Leave blank for automatic, or set 1 to render program colors exactly as sent.",
-            "automatic": "Automatic: {{light}} on light backgrounds, {{dark}} on dark.",
-            "disabled": "Correction off. Programs that rely on low contrast, like Powerline separators, render as sent.",
-            "pinned": "Targets {{ratio}}:1 contrast for foreground colors, where possible.",
-            "placeholder": "Auto",
-            "suffix": "blank = automatic, 1 = off"
           }
         },
         "TerminalSettingsPreview": {