feat(ui): promote next interface to default

[gcko]

Summary

• Promote the interface first released behind ?next=true to the canonical dashboard and remove the legacy frontend bundle, loader, routing branches, and escape hatch.
• Retire the old next query completely: URLs carrying the exact next parameter now return 404 instead of serving a compatibility alias; / and /?all=1 remain supported.
• Preserve the promoted interface's complete behavior: Attention routing, browser notifications on platforms without native notification support, and mobile breadcrumbs that remain usable with long labels.

User-facing verification

• Chrome: exercised Sessions, Projects, project detail, and session detail at 1531px desktop, 390px mobile, and 320px narrow-mobile widths with no horizontal overflow.
• Chrome: verified keyboard a/p/s navigation, populated Attention state, source-coverage disclosure, Copy ID feedback, touch-target sizing, and desktop/mobile breadcrumb behavior.
• Chrome: stress-tested a 104-character unbroken project label at mobile width; it wrapped without horizontal overflow.
• Confirmed the bare dashboard URL renders only the promoted interface with no legacy or mode-switch controls; HTTP integration tests verify the retired next query returns 404.

Test plan

• Ran the pre-PR suite in AGENTS.md § Pre-PR Checks (ruff, ruff format, mypy, lint_embedded.py, validate_plugins.py, bump_version.py --current, behavior-focused dashboard tests under coverage via discovery) and it is clean. Or the diff is prose only and validate_plugins.py is clean, per the short path documented there
• Preserved Python 3.11 compatibility; CI's runtime-floor job launches the shipped entry point on that floor
• Invoked the sync-docs skill — the doc updates for this change ride in this PR, or there was nothing to reconcile
• Behavior changes to server.py or cargento_runtime/ include a regression test
• No version field was touched (version-guard fails any PR that bumps one)
• Commits are signed off (git commit -s, DCO)

Additional results: 1,767 dashboard tests passed (1 skipped), 190 validation-script tests passed, coverage is 90.2%, two independent review lenses and a reproducing arbiter found no remaining Critical or Important issues, and native Claude/AGY plugin validation passed.

Generated with Codex.

[github-actions]

Coverage

Name                                                                  Stmts   Miss Branch BrPart  Cover
-------------------------------------------------------------------------------------------------------
cargento/skills/cargento/agy_hook.py                                     79     14     28      7  78.5%
cargento/skills/cargento/cargento_runtime/__init__.py                     0      0      0      0 100.0%
cargento/skills/cargento/cargento_runtime/aggregate.py                  213      1     64      0  99.6%
cargento/skills/cargento/cargento_runtime/asks.py                       110      0     28      0 100.0%
cargento/skills/cargento/cargento_runtime/claude_data.py                305     33    142     17  88.8%
cargento/skills/cargento/cargento_runtime/cli.py                        120     17     26      4  84.2%
cargento/skills/cargento/cargento_runtime/collectors/__init__.py          0      0      0      0 100.0%
cargento/skills/cargento/cargento_runtime/collectors/antigravity.py     410     41    166     25  87.2%
cargento/skills/cargento/cargento_runtime/collectors/claude.py          256     15     94     12  91.7%
cargento/skills/cargento/cargento_runtime/collectors/codex.py           101      7     38      7  89.9%
cargento/skills/cargento/cargento_runtime/collectors/copilot.py         148      6     50      2  96.0%
cargento/skills/cargento/cargento_runtime/collectors/cursor.py          276     19    104     16  90.3%
cargento/skills/cargento/cargento_runtime/collectors/droid.py            32      3      6      1  89.5%
cargento/skills/cargento/cargento_runtime/collectors/gemini.py           53      7     16      4  84.1%
cargento/skills/cargento/cargento_runtime/collectors/goose.py            89     11     28      4  87.2%
cargento/skills/cargento/cargento_runtime/collectors/opencode.py         78      6     26      2  92.3%
cargento/skills/cargento/cargento_runtime/collectors/pi.py              326     34    152     20  88.7%
cargento/skills/cargento/cargento_runtime/config.py                     189      1     20      1  99.0%
cargento/skills/cargento/cargento_runtime/diagnostics.py                 84      4     26      4  92.7%
cargento/skills/cargento/cargento_runtime/dismissals.py                 113      2     28      2  97.2%
cargento/skills/cargento/cargento_runtime/events.py                     169      0     64      0 100.0%
cargento/skills/cargento/cargento_runtime/git_status.py                  28      2      8      2  88.9%
cargento/skills/cargento/cargento_runtime/http_api.py                   520     36    172     10  93.1%
cargento/skills/cargento/cargento_runtime/io.py                         130      2     28      0  98.7%
cargento/skills/cargento/cargento_runtime/lifecycle.py                  325     15    106      6  95.1%
cargento/skills/cargento/cargento_runtime/notifications.py              174     14     60      4  91.5%
cargento/skills/cargento/cargento_runtime/observation.py                271      9     74      1  97.1%
cargento/skills/cargento/cargento_runtime/observer.py                   239     25    108     13  87.3%
cargento/skills/cargento/cargento_runtime/probe.py                       44      0     18      1  98.4%
cargento/skills/cargento/cargento_runtime/quota.py                      333      2    112      1  99.3%
cargento/skills/cargento/cargento_runtime/records.py                    262      6    116     10  95.8%
cargento/skills/cargento/cargento_runtime/sessions.py                   101      0     44      0 100.0%
cargento/skills/cargento/cargento_runtime/snapshot.py                    36      0      4      0 100.0%
cargento/skills/cargento/cargento_runtime/spacedock.py                  454     48    238     26  89.0%
cargento/skills/cargento/cargento_runtime/state.py                       66      0      2      0 100.0%
cargento/skills/cargento/cargento_runtime/stream.py                      57      0      8      0 100.0%
cargento/skills/cargento/cargento_runtime/transcripts.py                523     31    268     27  92.7%
cargento/skills/cargento/cargento_runtime/turns.py                      197     14    104     12  90.7%
cargento/skills/cargento/cargento_runtime/web/__init__.py                 0      0      0      0 100.0%
cargento/skills/cargento/cargento_runtime/web/page.py                    38      0     10      0 100.0%
cargento/skills/cargento/event_hook.py                                   86      4     28      3  93.9%
cargento/skills/cargento/mcp_server.py                                  377     22    112     14  92.2%
cargento/skills/cargento/notify_hook.py                                  49     15      6      1  67.3%
cargento/skills/cargento/server.py                                        3      0      2      1  80.0%
cargento/skills/cargento/statusline_hook.py                             131     13     46      8  87.0%
scripts/bench_collect.py                                                211     10     54      6  94.0%
scripts/bench_event_latency.py                                           67     21     14      1  67.9%
scripts/bump_version.py                                                  60     12     24      5  77.4%
scripts/capture_hook.py                                                 287     30     86     11  88.5%
scripts/derive_prompt_shapes.py                                         210     16     88     14  89.3%
scripts/lint_embedded.py                                                 89      3     28      2  95.7%
scripts/validate_plugins.py                                             675    190    390     60  69.2%
-------------------------------------------------------------------------------------------------------
TOTAL                                                                  9194    761   3464    367  90.1%

Threshold: fail_under in pyproject.toml · label coverage-exception to bypass (visible in PR timeline).