feat: extend session-adapter layer with codex-worktree + opencode adapters (#2145)

* feat: add codex-worktree session adapter

Adds the third session adapter (after dmux-tmux and claude-history),
normalizing Codex rollout sessions into the harness-neutral
ecc.session.v1 snapshot. Reads ~/.codex/sessions rollout JSONL,
derives objective (skipping the AGENTS.md preamble + leading message
UUID), model, originator, worktree cwd, and best-effort git branch.

This is step 1 of ECC-2.0-SESSION-ADAPTER-DISCOVERY (move the
abstraction beyond tmux + Claude-history) and supports the
wrap/adapt control-pane strategy: ECC reads sessions from any
harness rather than owning one UX.

- scripts/lib/session-adapters/codex-worktree.js: adapter + rollout parser
- canonical-session.js: normalizeCodexWorktreeSession
- registry.js: register adapter, codex/codex-worktree target types
- tests/lib/session-adapters-codex.test.js: 4 tests (unit + registry routing)

* feat: add opencode session adapter + allow empty intent objective

Adds the fourth session adapter (after dmux-tmux, claude-history,
codex-worktree), normalizing OpenCode sessions into ecc.session.v1.

Reads ~/.local/share/opencode/storage: session/<project>/ses_*.json
for metadata (id, directory, title, version, projectID, time) and
message/<session>/msg_*.json to extract the model (modelID/providerID
from the first assistant message). Derives objective from the session
title, treating the auto-generated "New session - <date>" title as no
objective. Recency-based active/recorded state.

Schema: relax intent.objective from non-empty to allow empty string
(ensureStringAllowEmpty). Sessions legitimately have no objective yet
(fresh/auto-titled), and claude-history already emitted "" via
metadata.title fallback. This fixes a latent over-strict validation.

- scripts/lib/session-adapters/opencode.js: adapter + storage parser
- canonical-session.js: normalizeOpencodeSession + ensureStringAllowEmpty
- registry.js: register adapter + opencode target type
- tests/lib/session-adapters-opencode.test.js: 5 tests

Tests: opencode 5/0, codex 4/0, session-adapters 14/0,
control-pane-state 10/0, session-inspect 8/0, control-pane 12/0.
Smoke-tested on a real OpenCode session (140 messages, gpt-5.3-codex).

* test: cover error/fallback branches for codex-worktree + opencode adapters

Lift global branch coverage past the 80% gate (was 79.53%). Adds error
and fallback path tests: missing-session/unknown-id throws, findRolloutById/
findSessionInfoById, direct file targets, objective truncation, model
fallbacks, corrupt-line skip, mtime activity fallback, and the real
resolveGitBranch path outside a repo.

codex-worktree.js branch 52.8%->78.3%; global branch 80.04%.

scripts/lib/session-adapters/registry.js

@@ -2,13 +2,18 @@
 
 const { createClaudeHistoryAdapter } = require('./claude-history');
 const { createDmuxTmuxAdapter } = require('./dmux-tmux');
+const { createCodexWorktreeAdapter } = require('./codex-worktree');
+const { createOpencodeAdapter } = require('./opencode');
 
 const TARGET_TYPE_TO_ADAPTER_ID = Object.freeze({
   plan: 'dmux-tmux',
   session: 'dmux-tmux',
   'claude-history': 'claude-history',
   'claude-alias': 'claude-history',
-  'session-file': 'claude-history'
+  'session-file': 'claude-history',
+  'codex-worktree': 'codex-worktree',
+  codex: 'codex-worktree',
+  opencode: 'opencode'
 });
 
 function buildDefaultAdapterOptions(options, adapterId) {
@@ -30,7 +35,9 @@ function buildDefaultAdapterOptions(options, adapterId) {
 function createDefaultAdapters(options = {}) {
   return [
     createClaudeHistoryAdapter(buildDefaultAdapterOptions(options, 'claude-history')),
-    createDmuxTmuxAdapter(buildDefaultAdapterOptions(options, 'dmux-tmux'))
+    createDmuxTmuxAdapter(buildDefaultAdapterOptions(options, 'dmux-tmux')),
+    createCodexWorktreeAdapter(buildDefaultAdapterOptions(options, 'codex-worktree')),
+    createOpencodeAdapter(buildDefaultAdapterOptions(options, 'opencode'))
   ];
 }
 
@@ -69,6 +76,20 @@ function normalizeStructuredTarget(target, context = {}) {
     };
   }
 
+  if (type === 'codex-worktree' || type === 'codex') {
+    return {
+      target: `codex:${value}`,
+      context: nextContext
+    };
+  }
+
+  if (type === 'opencode') {
+    return {
+      target: `opencode:${value}`,
+      context: nextContext
+    };
+  }
+
   return {
     target: value,
     context: nextContext