feat: bandarmology (idx stocks bandar, analyze_bandar)

`idx stocks bandar SYMBOL...` reads the broker summary: for the top 1, 3,
5 and 10 brokers per side, buy value minus sell value in basis points of
value traded, with a signal from big accumulation to big distribution on
the headline tier (--top, default 5). Several symbols give a screen ranked
by that figure (at most 100, one request each), which pipes from
`stocks screen`. The MCP server exposes it as analyze_bandar (20 symbols).

- analysis/bandar.rs is pure and versioned (`top_concentration_v1`):
  integer basis points, no figure missing counted as zero, buy/sell VWAP
  from exact averages, and the brokers on both sides listed because their
  gross figures overstate their direction.
- Thresholds (±5%/±15%) follow fzn0x/idx (MIT); docs call them heuristics.
- Invalid input fails a screen at once; other errors fail one symbol and
  are warned about on stderr.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V3syn2fN2LNo5pvTSqc6eh

web/src/content/docs/cli/reference.md

@@ -67,6 +67,7 @@ Commands:
   risk         Run risk analysis on a stock
   fundamental  Run full fundamental analysis on a stock
   broker       Which brokers bought and sold a stock
+  bandar       Bandarmology: is buying more concentrated than selling
   profile      Get company profile
   financials   Get financial statements
   earnings     Get earnings report
@@ -351,6 +352,83 @@ Examples:
   idx -o json stocks broker BBCA --investor foreign
 ```
 
+### `idx stocks bandar`
+
+```text
+Bandarmology from the broker summary: the top 1, 3, 5 and 10 buyers' value against the same number of sellers', as a share of value traded, with a signal from big accumulation to big distribution. Several symbols give a screen ranked by the headline tier (at most 100, one request each). A heuristic over end-of-day broker codes, not advice.
+
+Usage: idx stocks bandar [OPTIONS] <SYMBOLS>...
+
+Arguments:
+  <SYMBOLS>...
+          One or more symbols, comma-separated or space-separated; `-` reads them from stdin
+
+Options:
+      --date <DATE>
+          One session, YYYY-MM-DD. Default: the latest session with trades
+
+  -o, --output <OUTPUT>
+          Output format [default: auto = table on a terminal, json when piped]
+
+          [possible values: auto, table, json, jsonl]
+
+      --from <FROM>
+          First session of a range, YYYY-MM-DD (at most 366 days)
+
+      --no-color
+          Disable colored output
+
+  -q, --quiet
+          Suppress non-essential output
+
+      --to <TO>
+          Last session of the range, YYYY-MM-DD. Default: today
+
+      --investor <INVESTOR>
+          Whose trades to count
+
+          Possible values:
+          - all:      Every trade
+          - foreign:  Trades by foreign investors only
+          - domestic: Trades by domestic investors only
+
+          [default: all]
+
+  -v, --verbose...
+          Increase verbosity (-v, -vv)
+
+      --board <BOARD>
+          Which board's trades to count; `regular` leaves out negotiated block trades
+
+          Possible values:
+          - all:        Every board
+          - regular:    Regular market (RG), the continuous order book
+          - cash:       Cash market (TN)
+          - negotiated: Negotiated market (NG): pre-arranged block trades
+
+          [default: all]
+
+      --offline
+          Run without network requests
+
+      --no-cache
+          Bypass local cache
+
+      --top <TOP>
+          Tier behind the headline signal: 1, 3, 5 or 10 brokers per side
+
+          [default: 5]
+
+  -h, --help
+          Print help (see a summary with '-h')
+
+Examples:
+  idx stocks bandar BBCA
+  idx stocks bandar BBCA --from 2026-10-12 --to 2026-10-16 --top 3
+  idx stocks bandar BBCA,BBRI,BMRI,TLKM
+  idx stocks screen --filter high-volume | jq -r '.[].symbol' | idx stocks bandar -
+```
+
 ### `idx stocks profile`
 
 ```text