fix: handle missing scrip column in April 2026 KSEI PDF

The April 2026 IDX ownership PDF omits the zero-valued scrip column for
some holders, causing the parser to leave holdings_scripless/scrip as
empty strings. This broke normalize_ksei_row which called parse_id_number
on empty input.

Two-layer fix:
- Parser: pop_numeric_tail handles 2-column (missing scrip) rows by
  defaulting scrip to "0"
- Normalizer: parse_id_number_or_zero backstop treats empty component
  share fields as 0 while still requiring total_shares

Also includes AGENTS.md refresh, formatting cleanup (rustfmt), and
version bump to 0.2.2.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/cli/ownership.rs

@@ -14,11 +14,11 @@ use crate::error::IdxError;
 use crate::output::OutputFormat;
 use crate::output::json;
 use crate::output::table::format_idr;
-use crate::runtime;
 use crate::ownership::types::{
     ChangeType, FlowSignal, HolderRow, KseiHolding, OwnershipRelease, OwnershipSource,
 };
 use crate::ownership::{archive, db, entities, graph, parser, remote, search, snapshot};
+use crate::runtime;
 
 #[derive(Debug, Args)]
 #[command(