Add narrative text and a day-significance rank to the interpreter

Each of the day's top significant transits now gets a short sentence
describing what it classically means and which area of life its house
governs, condensed from Sepharial's Transits and Planetary Periods
(1920, public domain) plus a small table of traditional house
significations. The day-level line also shows its rank out of the 4
defined levels, e.g. "Notable (2/4)". Docs (CLAUDE.md, README,
docs/input-output-format.md, docs/reading.md) updated to match,
including a full worked example in docs/reading.md.

interpreter/src/main.c

@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "narrative.h"
 #include "reading_io.h"
 #include "significance.h"
 
@@ -12,7 +13,7 @@ static void print_usage(const char *prog) {
     "Reads a DailyReading in deck-engine's --format json shape - from the\n"
     "given file, or from stdin if no file is given (or it is \"-\") - and\n"
     "prints a significance report: the day's overall level and the top\n"
-    "aspects driving it.\n\n"
+    "aspects driving it, each with a short narrative note.\n\n"
     "Typical use:\n"
     "  dist/deck-engine ... --format json | %s\n"
     "  dist/deck-engine ... --format json > reading.json && %s reading.json\n",
@@ -115,7 +116,8 @@ int main(int argc, char **argv) {
   DailyInterpretation interp;
   interpret_daily_reading(&reading, &interp);
 
-  printf("Day significance: %s\n", day_level_name(interp.day_level));
+  printf("Day significance: %s (%d/%d)\n", day_level_name(interp.day_level),
+         interp.day_level + 1, DAY_SIGNIFICANCE_COUNT);
   if (interpretation_deserves_framing(&interp)) {
     printf("(a major transit today - worth a deeper Celtic Cross look)\n");
   }
@@ -137,6 +139,7 @@ int main(int argc, char **argv) {
     printf(" %s natal %s", aspect_display_name(a->type), body_display_name(a->natal_planet));
     print_body_in_sign(&reading.natal.bodies[a->natal_planet]);
     printf(" (orb %.1f\xc2\xb0, score %.2f)\n", a->orb, item->score);
+    narrative_print(stdout, "     ", a, reading.transits.bodies[a->transiting_planet].house);
   }
   return 0;
 }