Let --context expand any selection past its range, drawing from the whole file

docs/database.md

@@ -82,7 +82,7 @@ A revision number identifies a *state position between diffs*, not a diff:
 
 Like repeated `--grep` patterns (which must all match), repeated ranges are restrictive: `-r r1:r5 -r 0:2` prints only the first two records of those in the revision window, regardless of flag order. Plain ranges truncate Python-style and print nothing when the intersection is empty; a single plain index must exist and fails with exit code 2 otherwise.
 
-`--context N` (default 0) adds GNU grep-style context as the final step: each printed item is expanded by N surrounding records drawn from the records in the processed range, free of the `--grep` and plain-number filters, with overlapping expansions merged so nearby matches do not duplicate context records.
+`--context N` (default 0) adds GNU grep-style context as the final step: each printed item is expanded by N surrounding records drawn from the whole file — expanding whatever would be shown past any range restriction, so `-r s3 --context 2` shows that snapshot plus the two records before and after it. Overlapping expansions merge so nearby matches do not duplicate context records.
 
 The JSON dump (`-o`) and migrations operate on the state after the **last printed record**, whatever filtering produced the printout — so a plain `-r 2:5` dump ends at the 5th filtered record, and `--grep` or `--context` shift the dump to their last printed record as well. When nothing is printed (an empty filter result or `-q`), the dump falls back to the state at the end of the unit-spec window (or the end of the file).