Orbit: agent answers "why did my job fail?" by resuming an inaccessible history (403) and hallucinating a failure explanation

**App:** 0.5.1 (linux) · **Model:** kimi-k2.7-code (openai-compatible). Reported via beta feedback ("Total hallucination — the history does not exist").

## What happened

The user asked *"why my last galaxy job failed?"* The agent worked off the notebook-pages list instead of the user's own jobs:

1. `notebook_list_galaxy_pages` → returned a set of Galaxy pages
2. `notebook_resume_from_galaxy(page_id=…, history_id=…)` → linked to a history taken from one of those pages
3. `galaxy_history_show` → **tool not found** (the agent guessed a tool name that doesn't exist on the server)
4. `galaxy_get_history_contents(history_id=…)` → **403 `History is not accessible by user` (err_code 403002)** — that history isn't owned by the current user/API key

After the 403 it didn't surface the access error; it fabricated an answer about the inaccessible history — hence the reporter's "Total hallucination."

## The bugs

1. **Wrong data source for "my last job."** "Why did my last job fail?" should resolve against the user's *own* histories/jobs (`get_histories` / `list_history_ids` → recent jobs), not a history pulled from a notebook page that may belong to someone else.
2. **403 → confident hallucination.** A 403 / not-accessible (or a guessed tool that 404s) should be surfaced as "I couldn't access that history," not narrated around.

## Suggested direction

- Ground "my last job/history" queries in the user's accessible histories before answering.
- Treat a Galaxy 403 / not-accessible as a hard stop that's reported to the user, not something to invent a narrative around.

xref #261 (agent fabricates a tool-failure root cause), #210 (job errors not surfaced proactively).

Start by tracing the agent handling for “my last job” alongside notebook_list_galaxy_pages, notebook_resume_from_galaxy, get_histories, and list_history_ids. Check how galaxy_get_history_contents returns a 403 and how unknown tools are handled; done means accessible user histories are preferred and inaccessible or unavailable data is reported without an explanation being generated.

Written by the indexing model from the issue text.