fix(search): use explicit AND in FTS5 queries to fix apostrophe search

FTS5's implicit AND (space-separated tokens) silently fails when combined
with parenthesized OR groups produced by processPunctuatedWords. For example,
searching "you've got" generated the query `("you ve" OR youve*) got*` which
returned no results. Using explicit AND (`("you ve" OR youve*) AND got*`)
resolves this FTS5 quirk. Since implicit and explicit AND are semantically
identical in FTS5, this change is safe for all queries unconditionally.

persistence/sql_search_fts.go

@@ -178,7 +178,9 @@ func buildFTS5Query(userInput string) string {
 		tokens[i] = t + "*"
 	}
 
-	result = strings.Join(tokens, " ")
+	// Use explicit AND between tokens — FTS5's implicit AND (space-separated)
+	// doesn't work correctly with parenthesized OR groups from processPunctuatedWords.
+	result = strings.Join(tokens, " AND ")
 
 	for i, phrase := range phrases {
 		placeholder := fmt.Sprintf("\x00PHRASE%d\x00", i)

persistence/sql_search_fts_test.go

@@ -17,32 +17,33 @@ var _ = DescribeTable("buildFTS5Query",
 	Entry("returns empty string for empty input", "", ""),
 	Entry("returns empty string for whitespace-only input", "   ", ""),
 	Entry("appends * to a single word for prefix matching", "beatles", "beatles*"),
-	Entry("appends * to each word for prefix matching", "abbey road", "abbey* road*"),
+	Entry("appends * to each word for prefix matching", "abbey road", "abbey* AND road*"),
 	Entry("preserves quoted phrases without appending *", `"the beatles"`, `"the beatles"`),
 	Entry("does not double-append * to existing prefix wildcard", "beat*", "beat*"),
-	Entry("strips FTS5 operators and appends * to lowercased words", "AND OR NOT NEAR", "and* or* not* near*"),
-	Entry("strips special FTS5 syntax characters and appends *", "test^col:val", "test* col* val*"),
-	Entry("handles mixed phrases and words", `"the beatles" abbey`, `"the beatles" abbey*`),
-	Entry("handles prefix with multiple words", "beat* abbey", "beat* abbey*"),
-	Entry("collapses multiple spaces", "abbey   road", "abbey* road*"),
+	Entry("strips FTS5 operators and appends * to lowercased words", "AND OR NOT NEAR", "and* AND or* AND not* AND near*"),
+	Entry("strips special FTS5 syntax characters and appends *", "test^col:val", "test* AND col* AND val*"),
+	Entry("handles mixed phrases and words", `"the beatles" abbey`, `"the beatles" AND abbey*`),
+	Entry("handles prefix with multiple words", "beat* abbey", "beat* AND abbey*"),
+	Entry("collapses multiple spaces", "abbey   road", "abbey* AND road*"),
 	Entry("strips leading * from tokens and appends trailing *", "*livia", "livia*"),
-	Entry("strips leading * and preserves existing trailing *", "*livia oliv*", "livia* oliv*"),
+	Entry("strips leading * and preserves existing trailing *", "*livia oliv*", "livia* AND oliv*"),
 	Entry("strips standalone *", "*", ""),
-	Entry("strips apostrophe from input", "Guns N' Roses", "Guns* N* Roses*"),
+	Entry("strips apostrophe from input", "Guns N' Roses", "Guns* AND N* AND Roses*"),
 	Entry("converts slashed word to phrase+concat OR", "AC/DC", `("AC DC" OR ACDC*)`),
 	Entry("converts hyphenated word to phrase+concat OR", "a-ha", `("a ha" OR aha*)`),
 	Entry("converts partial hyphenated word to phrase+concat OR", "a-h", `("a h" OR ah*)`),
 	Entry("converts hyphenated name to phrase+concat OR", "Jay-Z", `("Jay Z" OR JayZ*)`),
 	Entry("converts contraction to phrase+concat OR", "it's", `("it s" OR its*)`),
-	Entry("handles punctuated word mixed with plain words", "best of a-ha", `best* of* ("a ha" OR aha*)`),
-	Entry("strips miscellaneous punctuation", "rock & roll, vol. 2", "rock* roll* vol* 2*"),
-	Entry("preserves unicode characters with diacritics", "Björk début", "Björk* début*"),
+	Entry("handles punctuated word mixed with plain words", "best of a-ha", `best* AND of* AND ("a ha" OR aha*)`),
+	Entry("handles contraction followed by plain words", "you've got", `("you ve" OR youve*) AND got*`),
+	Entry("strips miscellaneous punctuation", "rock & roll, vol. 2", "rock* AND roll* AND vol* AND 2*"),
+	Entry("preserves unicode characters with diacritics", "Björk début", "Björk* AND début*"),
 	Entry("collapses dotted abbreviation into phrase", "R.E.M.", `"R E M"`),
 	Entry("collapses abbreviation without trailing dot", "R.E.M", `"R E M"`),
-	Entry("collapses abbreviation mixed with words", "best of R.E.M.", `best* of* "R E M"`),
+	Entry("collapses abbreviation mixed with words", "best of R.E.M.", `best* AND of* AND "R E M"`),
 	Entry("collapses two-letter abbreviation", "U.K.", `"U K"`),
-	Entry("does not collapse single letter surrounded by words", "I am fine", "I* am* fine*"),
-	Entry("does not collapse single standalone letter", "A test", "A* test*"),
+	Entry("does not collapse single letter surrounded by words", "I am fine", "I* AND am* AND fine*"),
+	Entry("does not collapse single standalone letter", "A test", "A* AND test*"),
 	Entry("preserves quoted phrase with punctuation verbatim", `"ac/dc"`, `"ac/dc"`),
 	Entry("preserves quoted abbreviation verbatim", `"R.E.M."`, `"R.E.M."`),
 	Entry("returns empty string for punctuation-only input", "!!!!!!!", ""),