Remove the generated debug-client README (#25064)

Deletes `codex-rs/debug-client/README.md` as one step in removing the
stale app-server debug client.

This intentionally leaves Cargo workspace and lockfile cleanup for a
later follow-up PR.

codex-rs/debug-client/README.md

@@ -1,60 +0,0 @@
-WARNING: this code is mainly generated by Codex and should not be used in production
-
-# codex-debug-client
-
-A tiny interactive client for `codex app-server` (protocol v2 only). It prints
-all JSON-RPC lines from the server and lets you send new turns as you type.
-
-## Usage
-
-Start the app-server client (it will spawn `codex app-server` itself):
-
-```
-cargo run -p codex-debug-client -- \
-  --codex-bin codex \
-  --approval-policy on-request \
-  --output-file /tmp/app-server-server-json.jsonl
-```
-
-You can resume a specific thread:
-
-```
-cargo run -p codex-debug-client -- --thread-id thr_123
-```
-
-### CLI flags
-
-- `--codex-bin <path>`: path to the `codex` binary (default: `codex`).
-- `-c, --config key=value`: pass through `--config` overrides to `codex`.
-- `--thread-id <id>`: resume a thread instead of starting a new one.
-- `--approval-policy <policy>`: `untrusted`, `on-failure` (deprecated), `on-request`, `never`.
-- `--auto-approve`: auto-approve command/file-change approvals (default: decline).
-- `--final-only`: only show completed assistant messages and tool items.
-- `--output-file <path>`: write raw server JSONL to this file instead of stdout.
-- `--model <name>`: optional model override for thread start/resume.
-- `--model-provider <name>`: optional provider override.
-- `--cwd <path>`: optional working directory override.
-
-## Interactive commands
-
-Type a line to send it as a new turn. Commands are prefixed with `:`:
-
-- `:help` show help
-- `:new` start a new thread
-- `:resume <thread-id>` resume a thread
-- `:use <thread-id>` switch active thread without resuming
-- `:refresh-thread` list available threads
-- `:quit` exit
-
-The prompt shows the active thread id. Client messages (help, errors, approvals)
-print to stderr; raw server JSON prints to stdout so you can pipe/record it
-unless `--final-only` is set. Pass `--output-file <path>` to record raw server
-JSONL to a file instead of stdout.
-
-## Notes
-
-- The client performs the required initialize/initialized handshake.
-- It prints every server notification and response line as it arrives.
-- Approvals for `item/commandExecution/requestApproval` and
-  `item/fileChange/requestApproval` are auto-responded to with decline unless
-  `--auto-approve` is set.