fix(ghidra): reject relative installation and Java paths in doctor and setup

A relative GHIDRA_INSTALL_DIR (or JAVA_HOME) that resolved from the current
directory passed doctor's Ghidra inspection, so doctor reported a healthy
provider and setup wrote the relative path into the MCP registration, but
REA's configuration parser rejects relative paths, so `providers`,
`capabilities` and the registered MCP server all failed.

The installation inspection's configuration check now applies the same
absolute-path rule, judged by the inspected platform's path syntax, and
names the relative setting. Doctor reports the provider unavailable with
that reason, and setup, which registers only an available inspection's
environment, no longer writes the path.

Fixes #1183

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/ghidra/GhidraInstallation.test.ts

@@ -1,5 +1,6 @@
 import { describe, expect, it } from "vitest";
 
+import { projectGhidraDoctorInspection } from "./GhidraDoctor.js";
 import {
   ghidraJavaEnvironment,
   inspectGhidraInstallation,
@@ -378,3 +379,47 @@ describe("Ghidra release line and JDK bounds", () => {
     ).toMatchObject({ status: "available", javaVersion: "17.0.20.1" });
   });
 });
+
+describe("Ghidra configuration paths", () => {
+  it.each([
+    [{ installDir: "./ghidra" }, "GHIDRA_INSTALL_DIR must be absolute"],
+    [{ installDir: INSTALL, javaHome: "./jdk" }, "JAVA_HOME must be absolute"],
+    [
+      { installDir: "ghidra", javaHome: "jdk" },
+      "GHIDRA_INSTALL_DIR and JAVA_HOME must be absolute",
+    ],
+  ])(
+    "rejects relative paths that REA's configuration parser rejects (%o)",
+    (paths, detail) => {
+      const result = inspectGhidraInstallation(
+        { ...paths, platform: "linux", architecture: "x64" },
+        host(),
+      );
+      expect(result).toMatchObject({
+        status: "unavailable",
+        rejection: {
+          code: "not_configured",
+          reason: expect.stringContaining("reject relative paths"),
+        },
+      });
+      expect(result.checks).toContainEqual(
+        expect.objectContaining({ name: "configuration", detail }),
+      );
+      // Setup registers only an available inspection's environment.
+      expect(projectGhidraDoctorInspection(result)).toMatchObject({
+        available: false,
+        registrationEnvironment: {},
+      });
+    },
+  );
+
+  it("judges absolute paths by the inspected platform", () => {
+    const result = inspectGhidraInstallation(
+      { installDir: "C:\\ghidra", platform: "win32", architecture: "x64" },
+      host(),
+    );
+    expect(result.checks).toContainEqual(
+      expect.objectContaining({ name: "configuration", status: "passed" }),
+    );
+  });
+});

src/ghidra/GhidraInstallation.ts

@@ -306,13 +306,7 @@ const installationChecks = ({
   javaHome,
   host,
 }: GhidraInstallationCheckContext): readonly GhidraInstallationCheck[] => [
-  installationCheck({
-    name: "configuration",
-    passed: coordinates.installDir !== null,
-    code: "not_configured",
-    detail: coordinates.installDir ?? "GHIDRA_INSTALL_DIR is not set",
-    remediation: `Set GHIDRA_INSTALL_DIR to an extracted Ghidra ${ghidraReleaseLine()} release directory.`,
-  }),
+  configurationCheck(coordinates.installDir, javaHome, platform),
   installationCheck({
     name: "platform",
     passed: NATIVE_PLATFORMS[platform] !== undefined,
@@ -366,6 +360,40 @@ const installationChecks = ({
   ),
 ];
 
+/**
+ * REA's configuration parser, and so the MCP server and analysis, accept only
+ * absolute paths; a relative one that happens to resolve here must not pass.
+ */
+const configurationCheck = (
+  installDir: string | null,
+  javaHome: string | undefined,
+  platform: NodeJS.Platform,
+): GhidraInstallationCheck => {
+  const { isAbsolute } = platform === "win32" ? win32 : posix;
+  const relative = [
+    ...(installDir !== null && !isAbsolute(installDir)
+      ? ["GHIDRA_INSTALL_DIR"]
+      : []),
+    ...(javaHome !== undefined && !isAbsolute(javaHome) ? ["JAVA_HOME"] : []),
+  ];
+  if (installDir === null || relative.length === 0)
+    return installationCheck({
+      name: "configuration",
+      passed: installDir !== null,
+      code: "not_configured",
+      detail: installDir ?? "GHIDRA_INSTALL_DIR is not set",
+      remediation: `Set GHIDRA_INSTALL_DIR to an extracted Ghidra ${ghidraReleaseLine()} release directory.`,
+    });
+  const settings = relative.join(" and ");
+  return installationCheck({
+    name: "configuration",
+    passed: false,
+    code: "not_configured",
+    detail: `${settings} must be absolute`,
+    remediation: `Set ${settings} to ${relative.length === 1 ? "an absolute path" : "absolute paths"}. REA's analysis and MCP server reject relative paths even when they resolve from the current directory.`,
+  });
+};
+
 /** Project an installation probe into caller-visible, secret-free diagnostics. */
 export const ghidraInstallationDiagnostics = (
   inspection: GhidraInstallationInspection,