refactor(paths): replace 26 modules hardcoded ~/.pry/ with PRY_DATA_DIR

Each module did:
    X_DIR = Path(os.path.expanduser("~/.pry/x"))

After:
    from paths import PRY_DATA_DIR
    X_DIR = PRY_DATA_DIR / "x"

The module-level Path construction is preserved, so the rest of the
code is unchanged. PRY_DATA_DIR is read once at import (overridable via
the env var of the same name).

Verified:
- 407 tests collect (was 5 collection errors from a misplaced import)
- 83 sampled tests pass (intelligence, proxy_manager, x402, agency,
  gdpr, referrals, marketplace, api)
- 0 remaining hardcoded ~/.pry references in .py files

Follow-up: paths.py adds subdir(name) helper for new code that wants
auto-mkdir; existing modules still call .mkdir(exist_ok=True) themselves
to preserve the eager-init behavior they had before.

pipelines.py

@@ -3,6 +3,7 @@ JSON-defined workflow engine. Users define pipelines as structured steps,
 the engine executes them sequentially with branching and error handling.
 
 A UI can render these steps as drag-and-drop blocks."""
+from paths import PRY_DATA_DIR
 
 # SPDX-License-Identifier: MIT
 # Copyright (c) 2026 Rug Munch Media LLC
@@ -20,7 +21,7 @@ from typing import Any, cast
 
 logger = logging.getLogger(__name__)
 
-PIPELINE_DIR = Path(os.path.expanduser("~/.pry/pipelines"))
+PIPELINE_DIR = PRY_DATA_DIR / "pipelines"
 PIPELINE_DIR.mkdir(parents=True, exist_ok=True)
 
 # ── Step Types Registry ──