fix(chat): tell agents how to read the company link prefix from a task identifier (#19967)

## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work
> - Chat agents reply with links to tasks, approvals, runs and agent
profiles
> - Each link starts with the company prefix, for example
`/RUN/agents/<id>`
> - The chat guidance said to derive the prefix from the task
identifier, but it did not say how
> - An agent decided that `RUN-1` does not give the prefix and invented
one, so its links were broken
> - This pull request states how to read the prefix and forbids prefixes
built from names, slugs, hostnames or paths
> - The benefit is that agent profile links and other company links in
chat replies open the correct page

## Linked Issues or Issue Description

**What happened**

A person asked a CEO agent in chat to preview and then import a company
package. The chat task was `RUN-1`. The agent's reasoning said: "Task
identifier RUN-1 doesn't give prefix directly." The agent then linked
agent profiles as `/runner-e2e/agents/<id>`. Each link opened
"Organization not found: No organization matches prefix RUNNER-E2E".

**Expected behavior**

The agent links `/RUN/agents/<id>`. The guidance tells the agent that
the prefix is the identifier part before the final hyphen and number.

**Steps to reproduce**

1. Open a chat with a CEO agent in a company whose prefix differs from
its slugified name.
2. Ask it to do something with another agent, for example import a
package that creates an agent.
3. See that the reply can link `/<invented-prefix>/agents/<id>`, which
opens "Organization not found".

## What Changed

- Replace the task-link sentence in `AGENT_CHAT_DIRECTIVE`
(`server/src/services/agent-conversations.ts`). It now says that the
prefix is the identifier part before the final hyphen and number
(`RUN-1` gives `RUN`). It says that all company links use that prefix.
It forbids a prefix built from a company name, slug, hostname or path.
- Add a regression test in
`server/src/__tests__/agent-conversations.test.ts`.

## Verification

- `cd server && pnpm exec vitest run
src/__tests__/agent-conversations.test.ts` passes (46 tests).
- An end-to-end check runs the `companies.import-preview` chat eval with
this commit cherry-picked onto the eval branch.

## Risks

- Low risk. This changes only prompt guidance text. Runtime behavior
does not change.

## Model Used

- Anthropic Claude Opus 5.5 (`claude-opus-5-5`), with tool use and code
execution in Claude Code.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [ ] All Paperclip CI gates are green
- [ ] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

server/src/__tests__/agent-conversations.test.ts

@@ -994,6 +994,13 @@ describe("chat prompt policy", () => {
     expect(prompt).toContain("/<prefix>/agents/<urlKey or id>");
   });
 
+  it("says how to read the company link prefix from a task identifier so agent links are not guessed", () => {
+    expect(AGENT_CHAT_DIRECTIVE).toContain("The company prefix is the part of a task identifier before its final hyphen and number: for task RUN-1 the prefix is RUN.");
+    expect(AGENT_CHAT_DIRECTIVE).toContain("Never build a prefix from the company name");
+    const prompt = buildPaperclipTaskMarkdown({ issue: { id: "chat", identifier: "RUN-1", title: "Chat", workMode: "ask", conversationAgentId: "agent" } });
+    expect(prompt).toContain("for task RUN-1 the prefix is RUN");
+  });
+
   it("asks which record is meant before changing one of several matches", () => {
     expect(AGENT_CHAT_DIRECTIVE).toContain("matches several records you can access and nothing in the conversation selects one, ask which one before changing any of them");
     expect(AGENT_CHAT_DIRECTIVE).toContain("link each candidate");

server/src/services/agent-conversations.ts

@@ -110,7 +110,7 @@ Create ordinary assigned tasks; this conversation is never a parent. Choose the
 
 For review or follow-up tasks, include the existing source materials the assignee needs, not just task identifiers or a rubric. Read the source task's saved documents and comments, then copy the relevant existing content into the handoff or attach resources the recipient can actually read. A new task's tools may only expose its own documents and history. Supplying existing source material is coordination, not creating the assigned deliverable.
 
-For task links, use the company-prefixed relative path /<prefix>/issues/<identifier>, deriving the prefix from the returned task identifier. For approval links, use /<prefix>/approvals/<approvalId> with the same company prefix and the returned approval id, so the person can open the approval to decide it. An absolute URL is appropriate only when its actual origin was supplied by the platform. Never invent a hostname for a Paperclip link. For an execution run, link /<prefix>/agents/<agentId>/runs/<runId> using the run's returned agentId. Issue run listings (GET /api/issues/{id}/runs) return the run ID as runId; use id only from responses that return the run itself, such as GET /api/heartbeat-runs/{runId}. Run listings return agent IDs, not names: read the agent and name it rather than showing a raw ID.
+For task links, use the company-prefixed relative path /<prefix>/issues/<identifier>. The company prefix is the part of a task identifier before its final hyphen and number: for task RUN-1 the prefix is RUN. This conversation's own task identifier gives it, and every company link below (tasks, approvals, runs, agent profiles) uses that same prefix. Never build a prefix from the company name, a slug, a hostname or a file path. For approval links, use /<prefix>/approvals/<approvalId> with the same company prefix and the returned approval id, so the person can open the approval to decide it. An absolute URL is appropriate only when its actual origin was supplied by the platform. Never invent a hostname for a Paperclip link. For an execution run, link /<prefix>/agents/<agentId>/runs/<runId> using the run's returned agentId. Issue run listings (GET /api/issues/{id}/runs) return the run ID as runId; use id only from responses that return the run itself, such as GET /api/heartbeat-runs/{runId}. Run listings return agent IDs, not names: read the agent and name it rather than showing a raw ID.
 
 When a reply concerns a specific agent, such as one you paused, resumed, configured, or reported on, link its profile at /<prefix>/agents/<urlKey or id> using the agent's returned urlKey or id. A profile link is not a mention: use agent:// only when you intend to notify that agent.