Proofing: -ically adverbs such as "specifically" are no longer flagged (#1694) (#1854)

* #1694: -ically adverbs are no longer flagged as misspelled

English spelling accepts "-ally" adverbs built on an "-ic" adjective in the
word list (specific → specifically, scientific → scientifically), as Word does.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

* #1694: only -ic adjectives take -ally

Review (FredApps): the "-ally" → stem rule applied to every known word,
so "desktopally" was accepted. The rule is now "-ically" → "-ic"
(specifically → specific); other words don't take "-ally".

Test: non_ic_words_do_not_take_ally (desktop, house, final, green).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01P8veLveuUsJJm6UEcQPEuW

---------

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>

crates/proof/src/lib.rs

@@ -315,7 +315,7 @@ fn known_core(w: &str) -> bool {
         return true;
     }
     // Inflections.
-    let stems: [(&str, &[&str]); 12] = [
+    let stems: [(&str, &[&str]); 13] = [
         ("'s", &[""]),
         ("s", &[""]),
         ("es", &["", "e"]),
@@ -325,6 +325,8 @@ fn known_core(w: &str) -> bool {
         ("ing", &["", "e"]),
         ("ly", &["", "le"]),
         ("ily", &["y"]),
+        // specifically → specific (#1694): only -ic adjectives, so "desktopally" stays wrong.
+        ("ically", &["ic"]),
         ("er", &["", "e"]),
         ("est", &["", "e"]),
         ("ness", &[""]),
@@ -924,6 +926,27 @@ mod tests {
         assert!(suggest("Wrold", 3).contains(&"World".to_string()));
     }
 
+    /// #1694: `-ically` adverbs come from their `-ic` adjective (specific → specifically).
+    #[test]
+    fn ically_adverbs_are_known() {
+        for w in ["specifically", "scientifically", "automatically", "dramatically", "Specifically"] {
+            assert!(is_correct(w), "{w}");
+        }
+        for w in ["specificaly", "specifcally", "zzzically"] {
+            assert!(!is_correct(w), "{w}");
+        }
+    }
+
+    /// #1694 review: only `-ic` adjectives take `-ally`; other known words (dictionary or
+    /// supplement) don't.
+    #[test]
+    fn non_ic_words_do_not_take_ally() {
+        for (base, wrong) in [("desktop", "desktopally"), ("house", "houseally"), ("final", "finalally"), ("green", "greenally")] {
+            assert!(is_correct(base), "{base}");
+            assert!(!is_correct(wrong), "{wrong}");
+        }
+    }
+
     /// #520: common modern words (and their inflections) are known; misspellings still flagged.
     #[test]
     fn common_modern_words() {