diff --git a/frontend/src/components/shared/markdown-editor/markdown-editor-content-integrity.test.ts b/frontend/src/components/shared/markdown-editor/markdown-editor-content-integrity.test.ts
index e4e448be..4ef94bbf 100644
--- a/frontend/src/components/shared/markdown-editor/markdown-editor-content-integrity.test.ts
+++ b/frontend/src/components/shared/markdown-editor/markdown-editor-content-integrity.test.ts
@@ -135,4 +135,36 @@ describe('generative content-integrity — atoms survive load↔serialize across
             expect(out.includes(atom), `atom "${atom}" lost (i=${i}):\n${doc}\n-->\n${out}`).toBe(true);
         }
     });
+
+    // A raw `|` inside a table cell is the one context the single-atom oracle above cannot generate: marked
+    // splits the row on it before inline-tokenizing, so an unprotected pipe drops the trailing cells. Build
+    // tables whose cells carry pipe-bearing atoms inside code spans / Go actions, plus a sentinel trailing
+    // cell; assert the sentinel and the atom's words survive and the table converges.
+    it('pipe-bearing atoms inside table cells keep their row intact and converge', () => {
+        const rng = mulberry32(0x7ab1e);
+        const pipeAtoms = ['x | y', '{{.Host | lower}}', 'a || b', 'grep foo | wc -l', 'no-pipe-here'];
+
+        for (let i = 0; i < 120; i++) {
+            const rowCount = 1 + Math.floor(rng() * 3);
+            const rows: string[] = [];
+            const sentinels: string[] = [];
+
+            for (let row = 0; row < rowCount; row++) {
+                const atom = pipeAtoms[Math.floor(rng() * pipeAtoms.length)] as string;
+                const sentinel = `${WORDS[Math.floor(rng() * WORDS.length)]}${row}`;
+
+                sentinels.push(sentinel);
+                rows.push(`| \`${atom}\` | ${sentinel} |`);
+            }
+
+            const doc = `| code | note |\n| --- | --- |\n${rows.join('\n')}`;
+            const out = roundTrip(doc);
+
+            expect(roundTrip(out), `did not converge (i=${i}):\n${doc}\n-->\n${out}`).toBe(out);
+
+            for (const sentinel of sentinels) {
+                expect(out.includes(sentinel), `cell "${sentinel}" dropped (i=${i}):\n${doc}\n-->\n${out}`).toBe(true);
+            }
+        }
+    });
 });
diff --git a/frontend/src/components/shared/markdown-editor/markdown-editor-marked.ts b/frontend/src/components/shared/markdown-editor/markdown-editor-marked.ts
index 7bfbd058..0f8e903e 100644
--- a/frontend/src/components/shared/markdown-editor/markdown-editor-marked.ts
+++ b/frontend/src/components/shared/markdown-editor/markdown-editor-marked.ts
@@ -2,9 +2,11 @@ import type { JSONContent, MarkdownRendererHelpers } from '@tiptap/core';
 
 import { Extension } from '@tiptap/core';
 import { renderTableToMarkdown, Table } from '@tiptap/extension-table';
-import { Markdown } from '@tiptap/markdown';
+import { Markdown, MarkdownManager } from '@tiptap/markdown';
 import { Marked } from 'marked';
 
+import { escapeTablePipes } from './markdown-editor-table-pipes';
+
 // @tiptap/markdown parses with `marked`, which — unlike markdown-it's `html: false` — always tries to
 // interpret `<...>` as HTML. Our content uses literal XML-ish tags (`<container_environment>`, `<input>`)
 // that must survive verbatim; marked silently swallows the ones whose names match real HTML elements
@@ -66,12 +68,36 @@ const TunedMarkdownText = Extension.create({
     priority: 50,
 });
 
+// The load-side counterpart to TunedTable's save-side pipe escape: protect a `|` inside a code span / Go
+// action in a table cell BEFORE marked's table tokenizer splits the row (it splits raw `|` before inline
+// tokenization, dropping trailing cells). This has to patch MarkdownManager.parse on the PROTOTYPE, not the
+// instance: the Markdown extension parses the INITIAL `content` inside its own onBeforeCreate (before any
+// lower-priority extension can touch the manager), so an instance patch would miss the initial load. The
+// manager also lexes via `new Lexer()`, bypassing Marked.parse — so a marked-level hooks.preprocess never
+// runs. Idempotent + guarded; the escape is a no-op fast-path for content without a table.
+let isManagerParsePatched = false;
+
+const patchManagerParse = () => {
+    if (isManagerParsePatched) {
+        return;
+    }
+
+    isManagerParsePatched = true;
+
+    const proto = MarkdownManager.prototype as unknown as { parse: (markdown: string) => unknown };
+    const parse = proto.parse;
+
+    proto.parse = function tunedParse(markdown: string) {
+        return parse.call(this, escapeTablePipes(markdown));
+    };
+};
+
 // @tiptap/extension-table's renderTableToMarkdown is alignment-aware but never escapes pipes, so a literal
 // `|` a cell emits (even from inside inline code) would re-parse as a column delimiter on the next SAVE and
 // drop cells (tiptap PR #7884). renderTableToMarkdown emits cell content only via h.renderChildren, so wrapping
 // that one call to escape pipes fixes the save side, on the official alignment-aware renderer.
-// This does NOT (and cannot) help the LOAD side: a raw `|` inside inline code arriving in external markdown is
-// split by marked's GFM table tokenizer BEFORE the inline-code tokenizer runs — a marked limitation.
+// The LOAD side of the same class (a raw `|` inside inline code arriving in external markdown) is covered by
+// patchManagerParse above.
 export const TunedTable = Table.extend({
     renderMarkdown(node: JSONContent, helpers: MarkdownRendererHelpers) {
         const pipeEscaping: MarkdownRendererHelpers = {
@@ -83,7 +109,13 @@ export const TunedTable = Table.extend({
     },
 });
 
-export const createMarkdownLayer = () => [
-    Markdown.configure({ marked: createTunedMarked() as unknown as typeof import('marked').marked }),
-    TunedMarkdownText,
-];
+export const createMarkdownLayer = () => {
+    // Installed here (before `new Editor` consumes these extensions) so the prototype patch is in place
+    // when the Markdown extension parses the initial content during construction.
+    patchManagerParse();
+
+    return [
+        Markdown.configure({ marked: createTunedMarked() as unknown as typeof import('marked').marked }),
+        TunedMarkdownText,
+    ];
+};
diff --git a/frontend/src/components/shared/markdown-editor/markdown-editor-table-pipes.test.ts b/frontend/src/components/shared/markdown-editor/markdown-editor-table-pipes.test.ts
new file mode 100644
index 00000000..833ed71f
--- /dev/null
+++ b/frontend/src/components/shared/markdown-editor/markdown-editor-table-pipes.test.ts
@@ -0,0 +1,80 @@
+import { describe, expect, it } from 'vitest';
+
+import { escapeTablePipes } from './markdown-editor-table-pipes';
+import { roundTrip, setupEditorJsdom } from './markdown-editor-test-setup';
+
+setupEditorJsdom();
+
+describe('escapeTablePipes — pure pre-lex pipe protection', () => {
+    it('escapes a pipe inside a code span in a body row', () => {
+        expect(escapeTablePipes('| Op | Meaning |\n| --- | --- |\n| `x | y` | z |')).toBe(
+            '| Op | Meaning |\n| --- | --- |\n| `x \\| y` | z |',
+        );
+    });
+
+    it('escapes a pipe inside a Go-template action in a body row', () => {
+        expect(escapeTablePipes('| Var | Out |\n| --- | --- |\n| {{.X | upper}} | ok |')).toBe(
+            '| Var | Out |\n| --- | --- |\n| {{.X \\| upper}} | ok |',
+        );
+    });
+
+    it('leaves a plain-text pipe (real column delimiter) untouched', () => {
+        const table = '| a | b |\n| --- | --- |\n| 1 | 2 |';
+
+        expect(escapeTablePipes(table)).toBe(table);
+    });
+
+    it('does not double-escape an already-escaped pipe', () => {
+        const table = '| a | b |\n| --- | --- |\n| `x \\| y` | z |';
+
+        expect(escapeTablePipes(table)).toBe(table);
+    });
+
+    it('handles a multi-backtick code span', () => {
+        expect(escapeTablePipes('| a | b |\n| --- | --- |\n| ``x | y`` | z |')).toBe(
+            '| a | b |\n| --- | --- |\n| ``x \\| y`` | z |',
+        );
+    });
+
+    it('leaves an unclosed backtick run alone (not a code span)', () => {
+        const table = '| a | b |\n| --- | --- |\n| `x | y |';
+
+        expect(escapeTablePipes(table)).toBe(table);
+    });
+
+    it('never touches a fenced code block that happens to hold a table', () => {
+        const doc = '```\n| a | b |\n| --- | --- |\n| `x | y` | z |\n```';
+
+        expect(escapeTablePipes(doc)).toBe(doc);
+    });
+
+    it('ignores a non-table line whose text contains pipes in code', () => {
+        const prose = 'run `a | b` in the shell';
+
+        expect(escapeTablePipes(prose)).toBe(prose);
+    });
+
+    it('returns the input unchanged when there is no pipe at all', () => {
+        const doc = '# heading\n\nsome `code` here';
+
+        expect(escapeTablePipes(doc)).toBe(doc);
+    });
+});
+
+describe('table cell with a piped code span — content survives load and converges (H1)', () => {
+    it('keeps the trailing cell and preserves the code content', () => {
+        const out = roundTrip('| Op | Meaning |\n| --- | --- |\n| `x | y` | z |');
+
+        expect(out).toContain('z');
+        expect(out).toContain('`x \\| y`');
+        expect(roundTrip(out)).toBe(out);
+    });
+
+    it('keeps a Go-template action with a pipe inside a cell', () => {
+        const out = roundTrip('| Var | Out |\n| --- | --- |\n| {{.X | upper}} | done |');
+
+        expect(out).toContain('done');
+        expect(out).toContain('{{.X \\| upper}}');
+        expect(roundTrip(out)).toBe(out);
+    });
+});
diff --git a/frontend/src/components/shared/markdown-editor/markdown-editor-table-pipes.ts b/frontend/src/components/shared/markdown-editor/markdown-editor-table-pipes.ts
new file mode 100644
index 00000000..f0439045
--- /dev/null
+++ b/frontend/src/components/shared/markdown-editor/markdown-editor-table-pipes.ts
@@ -0,0 +1,153 @@
+// marked's GFM table tokenizer splits every row on raw `|` BEFORE inline tokenization, so a pipe inside a
+// code span (`` `x | y` ``) or a Go-template action (`{{.X | upper}}`) in a body cell creates a phantom
+// column and the trailing cells are silently DROPPED on load. The splitter does honor `\|` — and unescapes
+// it in the cell text — so pre-escaping those pipes before marked lexes protects the load side the same way
+// TunedTable's renderChildren escape protects the save side.
+//
+// Scope is deliberately conservative — only rows that marked itself would treat as a table:
+//   • the header/delimiter pair must already parse as a table (matching cell counts, delimiter has |/:) —
+//     escaping pipes in a NON-table line would surface literal `\|` (and could even turn a setext heading
+//     into a table by changing the header's cell count);
+//   • only BODY rows starting with `|` are transformed (header cell counts are structural; a body row is
+//     truncated/padded to the header width, so protecting its pipes only ever preserves more content);
+//   • fenced code blocks are never touched.
+
+const FENCE_LINE = /^ {0,3}(```|~~~)/;
+const TABLE_DELIMITER_LINE = /^ {0,3}\|? *:?-+:? *(?:\| *:?-+:? *)*\|? *$/;
+const BODY_ROW_LINE = /^ {0,3}\|/;
+const TEMPLATE_ACTION = /\{\{[^{}]*\}\}/g;
+
+const isEscapedAt = (text: string, offset: number): boolean => {
+    let isEscaped = false;
+    let index = offset;
+
+    while (--index >= 0 && text[index] === '\\') {
+        isEscaped = !isEscaped;
+    }
+
+    return isEscaped;
+};
+
+const escapeUnescapedPipes = (text: string): string =>
+    text.replace(/\|/g, (pipe, offset: number, source: string) => (isEscapedAt(source, offset) ? pipe : '\\|'));
+
+// Mirrors marked's splitCells: split on unescaped pipes, drop a blank leading/trailing cell.
+const countCells = (row: string): number => {
+    const cells = row
+        .replace(/\|/g, (pipe, offset: number, source: string) => (isEscapedAt(source, offset) ? pipe : ' |'))
+        .split(/ \|/);
+
+    if (cells.length > 0 && !cells[0]!.trim()) {
+        cells.shift();
+    }
+
+    if (cells.length > 0 && !cells.at(-1)!.trim()) {
+        cells.pop();
+    }
+
+    return cells.length;
+};
+
+const findCodeSpanCloser = (row: string, from: number, runLength: number): number => {
+    for (let index = from; index < row.length; index++) {
+        if (row[index] !== '`') {
+            continue;
+        }
+
+        let runEnd = index;
+
+        while (runEnd < row.length && row[runEnd] === '`') {
+            runEnd++;
+        }
+
+        if (runEnd - index === runLength) {
+            return index;
+        }
+
+        index = runEnd - 1;
+    }
+
+    return -1;
+};
+
+const escapeRowPipes = (row: string): string => {
+    let result = '';
+    let index = 0;
+
+    while (index < row.length) {
+        const char = row[index]!;
+
+        if (char !== '`') {
+            result += char;
+            index++;
+            continue;
+        }
+
+        let runEnd = index;
+
+        while (runEnd < row.length && row[runEnd] === '`') {
+            runEnd++;
+        }
+
+        const run = row.slice(index, runEnd);
+        const closerStart = findCodeSpanCloser(row, runEnd, run.length);
+
+        // An unclosed backtick run is literal content, not a code span.
+        if (closerStart < 0) {
+            result += run;
+            index = runEnd;
+            continue;
+        }
+
+        result += run + escapeUnescapedPipes(row.slice(runEnd, closerStart)) + run;
+        index = closerStart + run.length;
+    }
+
+    return result.replace(TEMPLATE_ACTION, (action) => escapeUnescapedPipes(action));
+};
+
+export const escapeTablePipes = (markdown: string): string => {
+    if (!markdown.includes('|')) {
+        return markdown;
+    }
+
+    const lines = markdown.split('\n');
+    let openFence: null | string = null;
+    let isChanged = false;
+
+    for (let index = 0; index < lines.length; index++) {
+        const line = lines[index]!;
+        const fence = FENCE_LINE.exec(line);
+
+        if (fence) {
+            openFence = openFence === fence[1] ? null : (openFence ?? fence[1]!);
+            continue;
+        }
+
+        if (openFence !== null || !line.includes('|')) {
+            continue;
+        }
+
+        const delimiter = lines[index + 1];
+
+        if (
+            delimiter === undefined ||
+            !TABLE_DELIMITER_LINE.test(delimiter) ||
+            !/[|:]/.test(delimiter) ||
+            countCells(line) !== countCells(delimiter)
+        ) {
+            continue;
+        }
+
+        for (let row = index + 2; row < lines.length && BODY_ROW_LINE.test(lines[row]!); row++) {
+            const escaped = escapeRowPipes(lines[row]!);
+
+            if (escaped !== lines[row]) {
+                lines[row] = escaped;
+                isChanged = true;
+            }
+        }
+    }
+
+    return isChanged ? lines.join('\n') : markdown;
+};