feat(check): remove the claude -p executor and --executor flag

BUGS.md

@@ -2,10 +2,10 @@
 
 These are bugs (or missing features) I've observed while working with `multi checks`.
 
-- [ ] Remove the `Claude -p` executor.
-
 - [ ] No use of Cersei workflows to chain multiple prompts together.
 
+- [ ] No GitHub Action available.
+
 - [ ] Logs no longer report the id of the check that failed (or the number of attempted retries)
 
 - [ ] Assemble_instructions is hard-coded: src/checks/executor/mod.rs:98 (definition), called from src/checks/executor/cersei.rs:110
@@ -18,10 +18,6 @@ These are bugs (or missing features) I've observed while working with `multi che
 
 - [ ] No limit on max turns.
 
-- [ ] No support for Fireworks AI.
-
-- [ ] No GitHub Action available.
-
 - [ ] No loading of skills.
 
 - [ ] No loading of RULES.md files from the .claude directory.
@@ -43,6 +39,10 @@ guaranteeing the terminal is restored on the way out.
 
 ## Fixes
 
+- [x] No support for Fireworks AI.
+
+- [x] Remove the `Claude -p` executor.
+
 - [x] No trace capture. We need a way to record all session traces so that we can analyze why they failed.
 
 - [x] Output is now hanging. I suspect this is recent (within the last few commits) and it started

CHECKS.md

@@ -2,19 +2,19 @@
 
 # Requirement Provider-Agnostic Execution
 
-The agent executor is swappable behind a trait so execution can run over different engines (the in-process `cersei-agent` executor, the legacy `claude -p` fallback, or a test fake) without rewriting the execution phase. This extensibility is the whole point of the configuration/executor seam.
+The agent executor is defined behind a trait so execution can run over the in-process `cersei-agent` executor or a test fake without rewriting the execution phase. This extensibility is the whole point of the configuration/executor seam.
 
 ## Check Boxed Executor Trait
 
-Inspect the Rust sources for the `multi check` feature. Confirm that agent execution is defined behind a trait (for example `CheckExecutor`) that is consumed as a boxed or `Arc`-wrapped, dynamically-dispatched trait object — for example a type alias of the form `Box<dyn CheckExecutor + Send + Sync>`, mirroring the existing `BoxedIngress`, `BoxedMonitor`, and `BoxedPlatform` aliases. The check passes only if the execution phase depends on this trait rather than naming a concrete executor type. Report a failure if the execution path references a concrete executor struct (such as the cersei or claude executor) directly instead of the trait object.
+Inspect the Rust sources for the `multi check` feature. Confirm that agent execution is defined behind a trait (for example `CheckExecutor`) that is consumed as a boxed or `Arc`-wrapped, dynamically-dispatched trait object — for example a type alias of the form `Box<dyn CheckExecutor + Send + Sync>`, mirroring the existing `BoxedIngress`, `BoxedMonitor`, and `BoxedPlatform` aliases. The check passes only if the execution phase depends on this trait rather than naming a concrete executor type. Report a failure if the execution path references a concrete executor struct (such as the cersei executor) directly instead of the trait object.
 
 # Requirement In-Process Agent Execution
 
-The default executor runs each check's agent **inside the CLI process** via the `cersei-agent` library — there is no longer any requirement to shell out to the `claude` CLI for a check to run. A `claude -p` executor is retained only as an optional, explicitly-selected migration fallback.
+The executor runs each check's agent **inside the CLI process** via the `cersei-agent` library — there is no requirement to shell out to any external CLI for a check to run.
 
 ## Check Default Executor Runs In-Process
 
-Inspect the executor implementations and how the default executor is selected from configuration. Confirm that the default execution engine builds and runs a `cersei_agent::Agent` in-process (calling its `run`/`run_stream` method) rather than spawning the `claude` CLI. Confirm that any use of `std::process::Command` / `tokio::process` to launch `claude -p` lives only in the non-default fallback executor, gated behind an explicit `executor` selection. The check fails if running a check with the default configuration requires spawning an external `claude` process.
+Inspect the executor implementation and how it is constructed from configuration. Confirm that the execution engine builds and runs a `cersei_agent::Agent` in-process (calling its `run`/`run_stream` method) rather than spawning an external process. The check fails if running a check requires spawning an external `claude` process.
 
 # Requirement Trustworthy In-Process Reporting
 
@@ -66,7 +66,7 @@ Inspect the execution phase. Confirm that checks are dispatched concurrently —
 
 # Requirement Concurrency Defaults To The Host's Core Count
 
-The concurrency cap is user-configurable (a `--concurrency` flag, layered the same way as `--provider`/`--model`/`--effort`/`--executor`), but absent any override its default must equal the number of CPU cores available on the machine running `multi check` — not a hardcoded constant. A fixed default either strands cores on big machines or overcommits small ones.
+The concurrency cap is user-configurable (a `--concurrency` flag, layered the same way as `--provider`/`--model`/`--effort`), but absent any override its default must equal the number of CPU cores available on the machine running `multi check` — not a hardcoded constant. A fixed default either strands cores on big machines or overcommits small ones.
 
 ## Check Default Concurrency Equals Available Parallelism
 
@@ -90,11 +90,11 @@ Confirm that the command exits with status code 0 when every requirement is sati
 
 # Requirement Layered Configuration
 
-The model, provider, effort, and executor are resolved from three sources with standard CLI precedence — flag, then environment, then config file (flag wins) — while credentials are read only from each provider's native environment variable, never from the config file.
+The model, provider, and effort are resolved from three sources with standard CLI precedence — flag, then environment, then config file (flag wins) — while credentials are read only from each provider's native environment variable, never from the config file.
 
 ## Check Precedence And Validation
 
-Inspect the configuration phase of `multi check`. Confirm that provider/model/effort/executor are merged from a config file, `MULTI_`-prefixed environment variables, and CLI flags, with flags overriding environment overriding file. Confirm the selected model is validated against a hardcoded allowlist of known IDs for the provider (an unknown ID is a clear error). The check fails if any of these values cannot be set from configuration, or if the merge precedence is not flag > env > file.
+Inspect the configuration phase of `multi check`. Confirm that provider/model/effort are merged from a config file, `MULTI_`-prefixed environment variables, and CLI flags, with flags overriding environment overriding file. Confirm the selected model is validated against a hardcoded allowlist of known IDs for the provider (an unknown ID is a clear error). The check fails if any of these values cannot be set from configuration, or if the merge precedence is not flag > env > file.
 
 ## Check Credentials Are Environment-Only
 

guides/checks.md

@@ -15,11 +15,9 @@ requirement is satisfied only if **all** of its checks pass (logical AND).
 ## ✅ Prerequisites
 
 - [ ] An API key for your chosen provider in the environment (e.g.
-      `ANTHROPIC_API_KEY`) — see [Configuration](#️-configuration). The default
+      `ANTHROPIC_API_KEY`) — see [Configuration](#️-configuration). The
       in-process executor talks to the provider directly; **no `claude` CLI is
-      required**. (The optional `claude -p` fallback — `--executor claude` — does
-      need the [`claude`](https://docs.claude.com/en/docs/claude-code) CLI on your
-      `PATH`.)
+      required**.
 - [ ] **macOS** — the MVP sandboxes each check with an APFS copy-on-write clone.
       Other operating systems are not yet supported.
 
@@ -159,15 +157,14 @@ Glob, plus the judge tool) — a verification agent observes, it does not mutate
 
 ## ⚙️ Configuration
 
-The default **provider**, **model**, **effort**, **executor**, and
-**concurrency** are resolved from three sources, in order of precedence
-(highest wins):
+The default **provider**, **model**, **effort**, and **concurrency** are
+resolved from three sources, in order of precedence (highest wins):
 
-1. **Flags** — `--provider`, `--model`, `--effort`, `--executor`,
-   `--concurrency` on `multi check`.
+1. **Flags** — `--provider`, `--model`, `--effort`, `--concurrency` on
+   `multi check`.
 2. **Environment** — `MULTI_`-prefixed vars mapped into the `checks` namespace,
    e.g. `MULTI_CHECKS_MODEL`, `MULTI_CHECKS_PROVIDER`, `MULTI_CHECKS_EFFORT`,
-   `MULTI_CHECKS_EXECUTOR`, `MULTI_CHECKS_CONCURRENCY`.
+   `MULTI_CHECKS_CONCURRENCY`.
 3. **Config file** — the `[checks]` table of `MultiTool.toml` (or `.json` /
    `.jsonc`), discovered up the directory tree like any MultiTool manifest.
 
@@ -176,7 +173,6 @@ The default **provider**, **model**, **effort**, **executor**, and
 provider    = "anthropic"          # anthropic | openai | gemini
 model       = "claude-sonnet-4-6"  # must be a known model ID for the provider
 effort      = "low"                # low | medium | high  → thinking-token budget
-executor    = "cersei"             # cersei (in-process, default) | claude (fallback)
 concurrency = 8                    # checks run at once; must be > 0 (default: CPU core count)
 
 # optional, non-secret base-URL overrides per provider
@@ -192,11 +188,8 @@ enable extended thinking (4096- and 8192-token budgets respectively), while
 `low` — the default — keeps thinking off for speed and cost, running the agent
 deterministically instead.
 
-The **`executor`** selects the execution engine. The default `cersei` runs each
-check as an in-process agent (native multi-provider model swapping, no external
-CLI). `claude` is the legacy `claude -p` shell-out fallback, kept selectable for
-migration while the in-process path is validated; it requires the `claude` CLI on
-your `PATH` and will be removed once cersei is proven out.
+Each check runs as an in-process agent (native multi-provider model swapping,
+no external CLI or subprocess).
 
 The **`concurrency`** flag caps how many checks run at once; it must be a
 positive integer (`0` is rejected with a clear error). Its default matches the