Release CX-Codex 2.7.3 session stability

[Qjzn]

What changed

• add persistent Plan mode, structured plan cards, implementation handoff, and authoritative thread-level goals
• move queued-message ownership to the durable 7420 server and fix stale terminal-snapshot settlement, same-second turn materialization, async queue overwrite, and exact server ordering
• recover optimistic messages across refresh and converge external session-log progress through a bounded recent projection plus one authoritative quiet-window refresh
• parse Codex file citations safely and use PDF.js legacy main/worker bundles for older Android WebViews
• make the Android Task Pet quiet, edge-docked, reply-cursor driven, foreground-aware, and bounded to three task rows
• add project-scoped OpenCodeReview rules, focused regressions, release notes, and the 2.7.3 version metadata

User impact

Queued work now continues after switching conversations, refreshing, or closing the Android Activity. Each queued message receives its own turn, delete/retry/reorder operations remain stable under concurrent persistence, and long conversations show recent progress without repeated 6-8 second full-history reads. Plan/goal workflows, local file previews, and Android task attention are more predictable and recoverable.

Validation

• npm.cmd run verify:release -- -AllowDirty -SchemaAudit warn
• npm.cmd run verify:frontend-normalizers
• npm.cmd run verify:server-modules
• npm.cmd run build:frontend
• npm.cmd run build:cli
• npm.cmd run test:7420:sidebar-data
• full 36-surface test:7420:frontend twice on the final queue path (540.2s and 590.3s)
• real queue execution: BASE -> A -> B, three distinct turns
• real queue reorder: BASE -> C -> A -> B, four distinct turns and authoritative server/history order
• production dependency audit with npm 10.9.3: 0 vulnerabilities across 131 production dependencies
• OpenCodeReview 1.8.6 delegated review of 26 changed files: no additional release blocker

Schema-audit counts match the committed governance checkpoint. The release remains candidate-reviewed until main CI and the tagged Release workflow publish and verify the source ZIP, signed APK, and SHA-256 assets.