Eliminate Python dependency: embed frontend assets in odoo-go

- Copy all OWL frontend assets (JS/CSS/XML/fonts/images) into frontend/
  directory (2925 files, 43MB) — no more runtime reads from Python Odoo
- Replace OdooAddonsPath config with FrontendDir pointing to local frontend/
- Rewire bundle.go, static.go, templates.go, webclient.go to read from
  frontend/ instead of external Python Odoo addons directory
- Auto-detect frontend/ and build/ dirs relative to binary in main.go
- Delete obsolete Python helper scripts (tools/*.py)

The Go server is now fully self-contained: single binary + frontend/ folder.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/account/static/tests/char_with_placeholder_field.test.js

@@ -0,0 +1,78 @@
+import { expect, test } from "@odoo/hoot";
+import { queryFirst } from "@odoo/hoot-dom";
+import {
+    contains,
+    defineModels,
+    fieldInput,
+    fields,
+    models,
+    mountView,
+} from "@web/../tests/web_test_helpers";
+import { defineAccountModels } from "./account_test_helpers";
+
+class Account extends models.Model {
+    _name = "account.account";
+    _inherit = [];
+
+    code = fields.Char({
+        string: "Code",
+        trim: true,
+    });
+    placeholder_code = fields.Char();
+
+    _records = [
+        {
+            id: 1,
+            placeholder_code: "Placeholder Code",
+        },
+    ];
+
+    _views = {
+        list: /* xml */ `
+            <list editable="top" create="1" delete="1">
+                <field name="placeholder_code" column_invisible="1" />
+                <field name="code" widget="char_with_placeholder_field" options="{'placeholder_field': 'placeholder_code'}" />
+            </list>
+        `,
+    };
+}
+
+defineAccountModels();
+defineModels([Account]);
+test.tags("desktop");
+test("List: placeholder_field shows as text/placeholder", async () => {
+    await mountView({
+        type: "list",
+        resModel: "account.account",
+    });
+
+    const firstCellSelector = "tbody td:not(.o_list_record_selector):first";
+
+    expect(`${firstCellSelector} span`).toHaveText("Placeholder Code", {
+        message: "placeholder_field should be the text value",
+    });
+
+    expect(`${firstCellSelector} span`).toHaveClass("text-muted", {
+        message: "placeholder_field should be greyed out",
+    });
+
+    await contains(firstCellSelector).click();
+    expect(queryFirst(firstCellSelector).parentElement).toHaveClass("o_selected_row", {
+        message: "should be set as edit mode",
+    });
+    expect(`${firstCellSelector} input`).toHaveValue("", {
+        message: "once in edit mode, should have no value in input",
+    });
+    expect(`${firstCellSelector} input`).toHaveAttribute("placeholder", "Placeholder Code", {
+        message: "once in edit mode, should have placeholder_field as placeholder",
+    });
+    await fieldInput("code").edit("100001", { confirm: false });
+
+    await contains(".o_list_button_save").click();
+    expect(firstCellSelector).toHaveText("100001", {
+        message: "entered value should be saved",
+    });
+    expect(firstCellSelector).not.toHaveClass("text-muted", {
+        message: "field should not be greyed out",
+    });
+});