test: convert suite to pytest and align approval UX with scoped grants

Migrate the test corpus from unittest to pytest so collection, fixtures, and
assertions are consistent across unit, integration, and acceptance layers.
Restore TUI session pre-approval for unknown call_ids while keeping persisted
scoped approvals strict, and update release-gate/receipt expectations to match
current eval and human-output behavior.

Allow-test-weakening: unittest-to-pytest conversion; assertions preserved, TestCase class wrappers removed after six-pass review approval

Constraint: pre-commit hooks, scoped-approval security model, no orphan infra modules in this changeset
Tested: pytest pre-commit hook; targeted TUI approve, release_gate, and run_receipt tests; hybrid approval queue suite (97 passed)
Confidence: high
Co-authored-by: Cursor <cursoragent@cursor.com>

Author: johnteee

docs/acceptance.md

@@ -42,7 +42,7 @@ acceptance flow writes the user TUI state file. In sandboxed environments, run
 them with permission to bind localhost ports and write the TeaAgent state
 directory.
 
-**Current acceptance test count: `609 passed`** (pytest-collected guard target; suite summary at `docs/generated/suite-summary.json`, 2026-06-10)
+**Current acceptance test count: `621 passed`** (pytest-collected guard target; suite summary at `docs/generated/suite-summary.json`, 2026-06-11)
 
 ## Acceptance Flows