chore: delete the v1 python test suite (#73)

The v1 socket-protocol python test suite in tests/ (driven by tests/cmux.py)
is superseded by tests_v2/, which now has full protocol parity. Deletes 85
files from tests/ plus scripts/run-tests-v1.sh (the manual VM runner for the
retired suite).

Two tests/ files stay because they're CI-wired in .github/workflows/ci.yml
and don't depend on the v1 protocol:
- test_cli_version_memory_guard.py (no socket protocol, standalone)
- test_workspace_churn_up_arrow_lag.py (ported to the v2 client in #71)

Also preserved: the CI/release-infrastructure guard scripts in tests/ (they
guard workflow/build/release config, not app socket behavior, so they're
unrelated to the v1 protocol) and tests/fixtures/ssh-remote, which tests_v2/
depends on.

Fixes the one stale living reference to the deleted layout in
docs/v2-api-migration.md. Dated historical changelog/checklist entries in
TODO.md, PROJECTS.md, and docs/agent-browser-port-spec.md that record past
VM validation runs are left untouched as historical record.

Part of the v1-protocol-deletion sequence (step 5).

Author: arzafran

docs/v2-api-migration.md

@@ -163,14 +163,15 @@ Debug / Test-only:
 
 ## Test Migration
 
-v1 suite stays in `tests/`.
+The v1 python suite (`tests/`, driven by `tests/cmux.py`) has been deleted now that `tests_v2/`
+has full protocol parity. Only CI-infrastructure guard scripts and the two CI-wired tests ported
+onto the v2 client remain in `tests/`.
 
 v2 suite lives in `tests_v2/` and should:
 - use a v2 JSON client (`tests_v2/programa.py`)
 - avoid depending on v1 text output formats
 
-VM runners:
-- v1: `ssh programa-vm 'cd /Users/programa/GhosttyTabs && ./scripts/run-tests-v1.sh'`
+VM runner:
 - v2: `ssh programa-vm 'cd /Users/programa/GhosttyTabs && ./scripts/run-tests-v2.sh'`
 
 ## Open Questions