feat!: remove the deep-research feature

The harness ships browser tools; orchestrating a multi-agent research
workflow on top of them is the agent's job, not this extension's. Drops
the skill, the /deep-research command, and the web-search-researcher
subagent config.

browser_web_search and browser_read_page are untouched — the two tests
that covered their pure parsers move to test/domains/, where the test
glob still picks them up.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

8 files changed, 0 insertions, 43 deletions

diff --git a/test/deep-research/agent-config-test.ts b/test/deep-research/agent-config-test.ts
deleted file mode 100644
index 025a844..0000000
--- a/test/deep-research/agent-config-test.ts
+++ /dev/null
@@ -1,43 +0,0 @@
-import { test, before, describe } from "node:test";
-import assert from "node:assert/strict";
-import { readFileSync } from "node:fs";
-import { join } from "node:path";
-
-describe("web-search-researcher subagent config references only real tools", () => {
-  let frontmatter: string;
-  let body: string;
-  let toolsLine: string;
-
-  before(() => {
-    const agentPath = join(import.meta.dirname, "..", "..", ".pi", "agents", "web-search-researcher.md");
-    const raw = readFileSync(agentPath, "utf8");
-    const fmMatch = raw.match(/^---\n([\s\S]*?)\n---/);
-    frontmatter = fmMatch ? (fmMatch[1] ?? "") : "";
-    body = fmMatch ? raw.slice(fmMatch[0].length) : raw;
-    toolsLine = frontmatter.split("\n").find((l) => l.startsWith("tools:")) ?? "";
-  });
-
-  test("S20: tools includes browser_web_search", () => {
-    assert.ok(toolsLine.includes("browser_web_search"));
-  });
-
-  test("S20: tools includes browser_read_page", () => {
-    assert.ok(toolsLine.includes("browser_read_page"));
-  });
-
-  test("S20: tools does NOT include web_search", () => {
-    assert.ok(!/\bweb_search\b/.test(toolsLine));
-  });
-
-  test("S20: tools does NOT include web_fetch", () => {
-    assert.ok(!/\bweb_fetch\b/.test(toolsLine));
-  });
-
-  test("S20: isolated: true is present", () => {
-    assert.ok(/^\s*isolated:\s*true\s*$/m.test(frontmatter));
-  });
-
-  test("S20: body has no WebSearch/WebFetch references", () => {
-    assert.ok(!/WebSearch|WebFetch/.test(body));
-  });
-});
diff --git a/test/deep-research/fixtures/article-capture.json b/test/domains/fixtures/article-capture.json
index df9c67c..df9c67c 100644
--- a/test/deep-research/fixtures/article-capture.json
+++ b/test/domains/fixtures/article-capture.json
diff --git a/test/deep-research/fixtures/google-serp-captcha.json b/test/domains/fixtures/google-serp-captcha.json
index 7c6610f..7c6610f 100644
--- a/test/deep-research/fixtures/google-serp-captcha.json
+++ b/test/domains/fixtures/google-serp-captcha.json
diff --git a/test/deep-research/fixtures/google-serp-empty.json b/test/domains/fixtures/google-serp-empty.json
index 34bb1dc..34bb1dc 100644
--- a/test/deep-research/fixtures/google-serp-empty.json
+++ b/test/domains/fixtures/google-serp-empty.json
diff --git a/test/deep-research/fixtures/google-serp-ok.json b/test/domains/fixtures/google-serp-ok.json
index 61aa483..61aa483 100644
--- a/test/deep-research/fixtures/google-serp-ok.json
+++ b/test/domains/fixtures/google-serp-ok.json
diff --git a/test/deep-research/fixtures/no-article-capture.json b/test/domains/fixtures/no-article-capture.json
index d367b7e..d367b7e 100644
--- a/test/deep-research/fixtures/no-article-capture.json
+++ b/test/domains/fixtures/no-article-capture.json
diff --git a/test/deep-research/readability-test.ts b/test/domains/readability-test.ts
index 211229d..211229d 100644
--- a/test/deep-research/readability-test.ts
+++ b/test/domains/readability-test.ts
diff --git a/test/deep-research/serp-parser-test.ts b/test/domains/serp-parser-test.ts
index 433c650..433c650 100644
--- a/test/deep-research/serp-parser-test.ts
+++ b/test/domains/serp-parser-test.ts