fix: add Python SDK filter param types

[realfishsam]

Summary

• Add Python TypedDicts for history, OHLCV, user-trade, and order-history params
• Export the new param types from the Python SDK package

Fixes #738
Fixes #737
Fixes #736

Test Plan

• python3 -m py_compile sdks/python/pmxt/models.py sdks/python/pmxt/init.py
• git diff --check

[realfishsam]

PR Review: PASS (NOT VERIFIED)

What This Does

Adds missing Python SDK TypedDict exports for history/OHLCV/my-trades/order-history parameter shapes.

Blast Radius

Python SDK type surface (pmxt.__init__ and pmxt.models) only.

Consumer Verification

Before (base branch):
Base Python users could call these APIs but could not import the specific parameter TypedDict names from the package model surface.

After (PR branch):
PR exports HistoryFilterParams, OHLCVParams, MyTradesParams, and OrderHistoryParams. Core build and Jest tests passed; root verification then failed because pytest is unavailable.

Test Results

• Build: PASS
• Unit tests: CORE PASS (24 suites, 644 tests; root verification blocked by missing pytest)
• Server starts: PASS during root verification
• E2E smoke: NOT VERIFIED (Python import/type smoke not run due pytest/env gap)

Findings

No blocking findings.

PMXT Pipeline Check

• Field propagation (3-layer): N/A
• OpenAPI sync: N/A
• Financial precision: N/A
• Type safety: OK
• Auth safety: N/A

Semver Impact

patch -- SDK typing/export fix.

Risk

Python package import smoke was not executed in this environment; change is limited to type definitions/exports.