umbrella bug issue for the OpenCode 2 lane (complements PR #487)

[blasphemy]

Short description

OpenCode 2 lane: ctx_* tools, sidebar/RPC data, /ctx-* commands, context numbers, /ctx-dream and compaction-off mode are all missing or broken

What happened?

On OpenCode 2 (plugin lane 0.42.6), a large part of Magic Context's surface never engages. Expected behaviour is parity with the OpenCode 1 lane.

Observed, in order of impact:

1. No agent tools. The ctx_* tool set (ctx_search, ctx_reduce, ctx_note, …) is never registered on the v2 lane, so the agent cannot use them at all.
2. Sidebar/status have no data. The v2 TUI is a pure RPC client (no direct SQLite access), and the v2 lane never starts the plugin's RPC server — so the sidebar renders zeros and /ctx-status has nothing to read.
3. /ctx-* TUI commands don't exist. Direct keymap registration fails because the host's keymap provider isn't mounted during plugin setup; the lane never falls back to a slot that is mounted.
4. Context numbers are wrong. The sidebar reads Context 0.0% · 0/200k: usage is never persisted on the v2 lane (v1 persists from its event handler), the harness-keyed model-limit cache is never warmed (so every limit falls back to the generic 200k instead of the model's real window), and model recovery for sessions without a live entry reads only the frozen v1 tables.
5. /ctx-dream can't run. The command isn't wired, and scheduled dream tasks that require a tool loop pile up as failures because v2 hidden completions have no tool loop.
6. Compaction-off projects get nothing. When MC compaction is disabled in config, the v2 lane early-returns, so those projects lose the tools, the RPC surface and the memory/docs injection too — unlike v1, where compaction-off only skips the compaction machinery.
7. Historian/recomp notify paths are inert on v2 (no SDK-client seam), and the historian runner can't reach the lane's hidden-completion executor.

Reproduction: run OpenCode 2 with the plugin enabled on any project; open the sidebar (zeros), check the available tools (no ctx_*), try /ctx- (no commands), run /ctx-dream (nothing). On a store migrated from OpenCode 1.18, the lane is additionally gated by the migrated-store guard (#477), which is a separate open PR.

Root causes (short)

• v2 registerContext registered neither the tool registry nor the RPC server, and its TUI never registered the command keymap layer.
• The lane has no event handler (by design), so the v1 usage-persistence path doesn't run there; the limit cache is keyed per harness and the opencode2 file was never created.
• The compaction-off switch was implemented as an early return instead of a mode that only skips compaction machinery.
• Model recovery preferred/only read the frozen v1 message tables.

Diagnostics

• Plugin version: 0.42.6
• OpenCode version: 2.0.10
• Platform: macOS arm64
• Client: OpenCode TUI (CLI)
• Harness: OpenCode 2 only. Pi/OMP are unaffected by the lane defects (two shared modules the fix touches — the dreamer task scheduler and the recomp orchestrator — are covered for Pi/oh-my-pi by the shared suite).

Evidence: sidebar shows Context 0.0% · 0/200k; session_meta.last_context_percentage/last_input_tokens stay at 0 despite active turns; the tool list contains no ctx_* entries; /ctx-status and /ctx-dream are absent from the command palette.

Log output (excerpts)

# sidebar with no live session data (pre-fix)
Context 0.0% · 0/200k

# dream tasks failing instead of being reported as unsupported (pre-fix)
[dreamer] task verify failed code=MC-D02 (transient=false): HiddenCompletionRefusal message="hidden_tools_unsupported: verify requires tools; opencode2 hidden completions have no tool loop"

Relationship to the fix

Draft PR #487 implements the lane fixes above (tools, RPC server, /ctx-* via the app slot, compaction-off mode, context numbers, /ctx-dream, plus review hardening). This issue is the umbrella approval request for that PR per CONTRIBUTING.md (an approved issue is required before the PR leaves draft); it complements the PR rather than closing it.

Related but distinct: #477 (migrated-store guard — required for the lane to engage on stores migrated from 1.18; excluded from #487 to avoid stepping on it), #483 (historian max_output_tokens on ChatGPT-subscription logins), #475 (migration 85 relabels a real OC2 host's rows), #481 (closed — failed historian runs leaving hidden sessions).

Diagnostics

Plugin version

0.42.6

OpenCode version

2.0.10

Platform

macOS

Client

OpenCode TUI (CLI)

Log output (optional)