D126 — Codex's config.toml: foreign tables written inside a managed block are relocated, not lost

Status: implemented (2026-08-04).

Decision. Before either Codex config.toml block rewrite, Cartographer moves out of the span every top-level table group that the block's next contents do not themselves declare (configurator.EvictForeignTablesFromBlock, internal/configurator/codextoml.go, sibling of D99's AdoptCodexOrphanTables). Foreign groups are cut from the span, verbatim, and re-inserted, in file order, immediately before the begin marker line, separated from their neighbours by at most one blank line (joinSeam); a key declared both inside the span and in the block's next contents is left alone — it is ours, blocktext.Write will overwrite it. Both call sites (registerHookConfigTOML in internal/provisioning/hooksettings.go, and the .toml branch of configurator.Apply) run the new eviction before D99's adoption and before blocktext.Write, so a table that is both foreign-in-span and adoption-owned collapses to one copy instead of a duplicate key. Purely textual, as D58 requires: no parse/re-serialize, every byte outside the moved spans preserved.

Rationale. D99 made the write path idempotent against Codex's own rewrites by adopting the marker-less copies of tables Cartographer owns. It did not cover the mirror case: Codex records its per-hook trusted-hash bookkeeping ([hooks.state."<config path>:<event>:<i>:<j>"]) positionally after the last [[hooks.*]] table in the file — which, in a Cartographer-managed config.toml, is the one inside our own span. blocktext.Write replaces everything between its markers, so those tables were silently destroyed on the next connect/sync, even though codexHookTableOwner (D99) deliberately excludes [hooks.state] from adoption specifically to leave Codex's own bookkeeping alone — the write path was destroying what the adoption predicate was written to protect. Rewriting the relocated tables in canonical form would mean parsing/re-serializing config.toml, which D58 forbids; relocating them verbatim keeps the invariant that Cartographer owns only the text it wrote.

Consequences. Codex no longer loses the trust record for hooks it had already approved when the state table happens to fall inside a managed block. EvictForeignTablesFromBlock reports each relocation as its own warning, mirroring D99's phrasing. The fix lives in internal/configurator next to the existing codextoml.go line/header/span primitives it reuses, not in internal/blocktext — that package stays provider-agnostic (it also serves the AGENTS.md/CLAUDE.md instruction block).