feat: shareholder movements from the Stockbit session (ownership movements)

`idx ownership movements [SYMBOL]` and the MCP tool
`get_shareholder_movements` list reported changes in insiders' and major
holders' stakes, newest first, from Stockbit's
/insider/company/majorholder: IDX insider disclosures (any size, with the
trade price) and KSEI changes of holders at 5% and above (Stockbit's
estimated price). Stockbit filters by date range, holder id, action and
source; each page is 50 rows and one request, up to 10 pages, cached an
hour per page under every filter.

Rows keep exact signed share counts and the stake in basis points as
Stockbit rounds it; unknown action labels are kept as `other` rather than
dropped. JSON is {movements, more}; JSONL is one movement per line. The
command lives under `ownership` but needs no import, and `ownership`
commands now take --offline / --no-cache for it.

The per-symbol summary score is the next PR; docs/STOCKBIT.md records the
endpoint's parameters and action types as checked on 2026-11-03.

Claude-Session: https://claude.ai/code/session_01RqPPVeVDrnLoP7NUZmLRxY

README.md

@@ -98,7 +98,8 @@ idx ownership changes --from 2026-07-31 --to 2026-08-31
   market is open, delayed at least 10 minutes. With your own account
   (`idx stockbit login`): `stocks orderbook` depth, live
   quotes, Stockbit daily history, and corporate actions (`stocks actions`,
-  `stocks calendar`: dividends, rights, splits, meetings, IPOs and more). Personal use under Stockbit's terms; see
+  `stocks calendar`: dividends, rights, splits, meetings, IPOs and more), and
+  insider and major holder buys and sells (`ownership movements`). Personal use under Stockbit's terms; see
   the [Stockbit page](https://idx.rasyidanaf.com/cli/stockbit/)
 - Local file cache with TTL, and `--offline` mode with stale-cache fallback
 
@@ -166,9 +167,9 @@ change it to `auto` with `idx config set general.output auto`.
 
 ## MCP server
 
-`idx-mcp` serves the same data to MCP clients over stdio, as 20 tools:
+`idx-mcp` serves the same data to MCP clients over stdio, as 21 tools:
 `get_quotes`, `get_intraday`, `get_orderbook`, `get_corporate_actions`,
-`get_corporate_calendar`, `stockbit_status`, `stockbit_login`, `get_price_history`, `screen_stocks`, `get_company`,
+`get_corporate_calendar`, `get_shareholder_movements`, `stockbit_status`, `stockbit_login`, `get_price_history`, `screen_stocks`, `get_company`,
 `analyze_stock`, `compare_stocks`, `get_broker_summary`, `analyze_bandar`,
 `get_foreign_flow`, `get_shareholders`, `get_investor_holdings`,
 `search_investors`, `get_ownership_changes`, and `ownership_status`. Live results come wrapped as