feat(mcp): add idx-mcp, a stdio MCP server over idx-core

Phase 4 of docs/DESIGN.md. Eleven grouped tools (quotes, history, screen,
company, analysis, compare, shareholders, investor holdings, search,
ownership changes, status); ownership_sync is listed only with
--allow-sync. Live results keep the Fetched envelope, errors use the CLI's
{error, code, message} body, and investor tools on an empty database
point at the sync path.

idx-core gains Period/Interval FromStr, Investor::status, a ticker
filter on changes, and Display for ErrorCode (now used by the CLI too).
CLI output and goldens are unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/idx-mcp/src/params.rs

@@ -0,0 +1,177 @@
+//! Tool inputs. String enums are validated by idx-core's `FromStr`, so the
+//! accepted values and error messages match the CLI; the schemas list them.
+
+use idx_core::api::types::{Interval, Period};
+use idx_core::market::{ScreenFilter, ScreenRegion};
+use schemars::{JsonSchema, Schema, SchemaGenerator, json_schema};
+use serde::Deserialize;
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub struct SymbolsParams {
+    /// IDX tickers, e.g. ["BBCA", "BBRI"]; the `.JK` suffix is optional.
+    pub symbols: Vec<String>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub struct HistoryParams {
+    /// IDX ticker, e.g. "BBCA".
+    pub symbol: String,
+    /// Lookback window (default "3mo").
+    #[serde(default)]
+    #[schemars(schema_with = "period_schema")]
+    pub period: Option<String>,
+    /// Candle size (default "1d").
+    #[serde(default)]
+    #[schemars(schema_with = "interval_schema")]
+    pub interval: Option<String>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub struct ScreenParams {
+    /// Screen to run (default "top-performers").
+    #[serde(default)]
+    #[schemars(schema_with = "filter_schema")]
+    pub filter: Option<String>,
+    /// Market region (default "id").
+    #[serde(default)]
+    #[schemars(schema_with = "region_schema")]
+    pub region: Option<String>,
+    /// Maximum results (default 50).
+    #[serde(default)]
+    pub limit: Option<usize>,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Deserialize, JsonSchema)]
+#[serde(rename_all = "lowercase")]
+pub enum CompanySection {
+    Profile,
+    Financials,
+    Earnings,
+    Sentiment,
+    Insights,
+    News,
+}
+
+impl CompanySection {
+    pub const ALL: [Self; 6] = [
+        Self::Profile,
+        Self::Financials,
+        Self::Earnings,
+        Self::Sentiment,
+        Self::Insights,
+        Self::News,
+    ];
+
+    pub fn as_str(self) -> &'static str {
+        match self {
+            Self::Profile => "profile",
+            Self::Financials => "financials",
+            Self::Earnings => "earnings",
+            Self::Sentiment => "sentiment",
+            Self::Insights => "insights",
+            Self::News => "news",
+        }
+    }
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub struct CompanyParams {
+    /// IDX ticker, e.g. "BBCA".
+    pub symbol: String,
+    /// Sections to fetch (default: all).
+    #[serde(default)]
+    pub sections: Option<Vec<CompanySection>>,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Deserialize, JsonSchema)]
+#[serde(rename_all = "lowercase")]
+pub enum AnalysisKind {
+    Technical,
+    Growth,
+    Valuation,
+    Risk,
+}
+
+impl AnalysisKind {
+    pub const ALL: [Self; 4] = [Self::Technical, Self::Growth, Self::Valuation, Self::Risk];
+
+    pub fn as_str(self) -> &'static str {
+        match self {
+            Self::Technical => "technical",
+            Self::Growth => "growth",
+            Self::Valuation => "valuation",
+            Self::Risk => "risk",
+        }
+    }
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub struct AnalyzeParams {
+    /// IDX ticker, e.g. "BBCA".
+    pub symbol: String,
+    /// Analyses to run (default: all).
+    #[serde(default)]
+    pub kinds: Option<Vec<AnalysisKind>>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub struct ShareholdersParams {
+    /// IDX ticker, e.g. "BBCA".
+    pub ticker: String,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub struct EntityParams {
+    /// Investor name or part of it, e.g. "DWIMURIA"; the closest match is used.
+    pub entity: String,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub struct SearchParams {
+    /// Full-text query over investor names.
+    pub query: String,
+    /// Maximum results (default 20).
+    #[serde(default)]
+    pub limit: Option<usize>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub struct ChangesParams {
+    /// Earlier release date, YYYY-MM-DD (see ownership_status).
+    pub from: String,
+    /// Later release date, YYYY-MM-DD.
+    pub to: String,
+    /// Only this ticker's changes.
+    #[serde(default)]
+    pub ticker: Option<String>,
+    /// Maximum rows returned (default 200); `total` reports the full count.
+    #[serde(default)]
+    pub limit: Option<usize>,
+}
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub struct SyncParams {
+    /// Re-download even when the local snapshot is current.
+    #[serde(default)]
+    pub force: bool,
+}
+
+fn string_enum(values: Vec<&'static str>) -> Schema {
+    json_schema!({ "type": "string", "enum": values })
+}
+
+fn period_schema(_: &mut SchemaGenerator) -> Schema {
+    string_enum(Period::ALL.iter().map(Period::as_str).collect())
+}
+
+fn interval_schema(_: &mut SchemaGenerator) -> Schema {
+    string_enum(Interval::ALL.iter().map(Interval::as_str).collect())
+}
+
+fn filter_schema(_: &mut SchemaGenerator) -> Schema {
+    string_enum(ScreenFilter::ALL.map(ScreenFilter::as_str).to_vec())
+}
+
+fn region_schema(_: &mut SchemaGenerator) -> Schema {
+    string_enum(ScreenRegion::ALL.map(ScreenRegion::as_str).to_vec())
+}