meshbay.git/packages/meshbay-common/src/meshbay_common/device.py, branch 0.15

docs: cite MESHBAY_DESIGN.md and a section instead of the merged notes

2026-09-19T00:12:47Z

The per-feature design notes were merged into docs/MESHBAY_DESIGN.md and deleted from the tree on 2026-09-11, but ~230 comments across the three packages still named them — usually written `docs/musicbay.md §3.2`, as though the file were still in docs/. A reader had to know §16 existed to resolve any of them. They now name the section directly. Every mapping comes from §16, the concordance, which already records where each old section landed: musicbay -> §9.8, mediacenter -> §9.7 for the Videos app and §6.5 where the subject is derived data, photos -> §9.9, auth-confirm -> §3.6, refactoring-search -> §9.11, invite-pairing-v1 -> §3.4, per-node-identity-v1 -> §3.2, captcha -> §7.7, chat-sender-keys -> §4.5, apps/refactor-groups -> §9.1–§9.4, desktop-client-v1 per section. Bare citations of the same documents (`draft-v6 §2.11`, `§4.8`, `§3.4`) are retargeted too: those collide with real section numbers in the design document, so leaving them would have been worse than the named form. Four cases the concordance does not cover, each decided rather than guessed: Sub-item references into documents that no longer exist — mediacenter's `§3.3 row 4`, `§3.4b/c`, `apps.md §3b` — name rows and sub-items §9.7 and §9.2 do not reproduce. The module-level citation stays; the sub-item pointer is dropped. The V-findings keep their labels but lose the dead `§10.1/` prefix. §13.8 lists V1–V13 as per-application open items, which is not what the labels mean in these comments, so pointing them at §13.8 would have been a false citation. `apps.md §5`'s virtualization requirement has no counterpart anywhere in the design document. The requirement is stated in the comment itself, so the citation is dropped rather than aimed at a section that does not say it. Comments that attributed a *sentence* to an old note — musicbay's "several thousand files" example, its "what got measured" note, its measured ~11%/~26% cover-art figures, the "original no root, whole shared tree" call — state the fact without attribution now. §9.8 does not contain those sentences and citing it for them would have been wrong. CLAUDE.md's "a reference to a document that no longer exists" row now says the concordance is for git history and out-of-tree material; the code cites sections directly. Verified: 2851 passed, 4 skipped. The 12 errors in the run are the Firefox leg of test_sticky_header.py's browser harness, which is broken at the browser level on this machine — headless Firefox (snap) dies with `[GFX1-]: RenderCompositorSWGL failed mapping default framebuffer`, renders nothing, and the probe exits `{"error": "no measurement"}` after its full 90s wait. Chrome runs the same 12 assertions in 3.2s and passes. Nothing here can affect it: every changed line in style.css is inside a comment. Also checked: ast.parse on every changed .py, `node --check` on every changed .js, the /* */ balance in style.css, and that no changed line exceeds the width its file already used. Co-Authored-By: Claude Opus 5

feat(chat): encrypt group chat under per-device epoch keys (MNP 2.0)

2026-09-07T15:50:28Z

Chat messages are sealed with AES-256-GCM under a key derived per group, per epoch, per *device*, and signed over the ciphertext with the device key the node pinned. The node relays and archives; it cannot read a message. There is no switch. MNP goes to 2.0 and MNP_MIN_SUPPORTED moves with it, so a 1.x peer is refused at the handshake with `version_too_old` rather than admitted and then unable to speak. An opt-in flag was designed and rejected: every node is a test node, so it would have bought nothing and left a plaintext branch reachable — C6's lesson one feature later. A test reads the source and refuses any code that consults a `chat_encrypted` setting. Not Sender Keys, and `senderkeys.py` is now documented as unused. With distribution under the group key and a node that serves history to devices which were not present, the node must retain each chain's earliest key, and a chain key at iteration i yields every message key from i on by pure HKDF — forward secrecy is zero either way. What the ratchet was left buying was stateful client code with silent failure modes, three of them reproduced: any member could sign as any other, a second device dropped the first's chain, and the skipped-key cache grew without bound. The reasoning is in docs/chat-sender-keys.md, which is the specification and the decision record. Epochs, not rotation: the epoch key is wrapped under the group key at delivery and never stored under it, so `gek_rotate` is a re-wrap. A group-key-derived archive key would have made every message ever sent unreadable on the first `member unpin`, which is the documented step after removing a member. A new epoch opens on member revoke/unpin, device revoke and `gek_rotate`; old epochs are kept and still delivered, so history stays readable to everyone who could already read it, and nothing anywhere deletes one. Three prerequisites this needed, each a live defect on its own: * The peer registry was keyed by user_id, so one account's second device evicted the first and the broadcast skipped recipients by account — a person's phone never saw what they typed on their laptop. * The handshake authenticated an account, never a device. `device_hello` (additive, signed, refused unless the key is a live device of this account in the node's own roster) is what lets the node refuse a member claiming somebody else's key. * `_admin_exec_file_delete` authorized against the exact uploading key, so device linking had already broken deleting your own file from your other device. It now authorizes against any non-revoked device of `uploader_id`. Found by driving the real panel over the real transport, not by reading source: `chat_keys_resp` was routed by arrival order and handed to an unanswered `media_meta_req` — the original frozen-tab defect in a message type that did not exist when that probe was written. And `_asText` had been deleted with an unrelated helper beside it; its only caller sits inside a promise the panel catches, so every conversation rendered empty with nothing in the console. Existing node data is migrated by QE/migration/migrate_chat_encryption.py (not versioned, per the QE rule), run with the node stopped. Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_01TZZxYjz8YeWRz13xDi8LJr

feat: device linking, and signing in to the hub with a device key

2026-08-18T01:24:55Z

Stage C. Identity keys are per node, so a browser and a desktop client are two keys on one account there — and the node refused the second where it accepted the first. Without this, an account created natively could never be opened in a browser without an operator code per node, and "a native client must not prevent web use" would have been dead on arrival. Device linking (node) --------------------- `identities` is keyed by `(user_id, pk_ed25519)` instead of `user_id` alone. The old shape did `INSERT OR REPLACE`, so a second device overwrote the first silently; SQLite cannot change a primary key in place, so the table is rebuilt. Existing pins are carried over — verified against a live roster with 10 of them, nobody re-pairs. A new device files a request bound by `sha256(code ‖ its own keys)`, and a key the node **already pinned** countersigns it. The hub cannot: it has stored no user keys since 2026-08-14, which is what makes this safe to do without an operator in the loop. **The code never reaches the node.** It lists this account's pending requests with their stored hashes; the approver recomputes and keeps the match. A node offering fabricated keys would have to produce a hash over a code it has never seen. Nothing rests on a human comparing digits — that ritual was dropped in 12.1 as "correct, unusable as the default" and must not return by the back door. The design document had the approver look a request up *by* its hash, which is circular: computing it needs the keys being asked about. Corrected in both. Revocation marks rather than deletes, because a deleted row is a key the node would happily pin again — which is the laptop somebody just reported lost. Your last device cannot be revoked: coming back would need an operator's code. Hub — the only change in the whole plan --------------------------------------- `POST /v1/users/auth` signs in with a device Ed25519 key, on the same pattern as `/v1/nodes/auth`, plus `/v1/users/devices` to register, list and retire. New `user_devices` table with an Alembic migration, because `create_all()` is not one. This is **not** the key directory that was H3, and the tests say so: nothing reads it but the hub, no group key is ever wrapped for one, and it is a different key from the per-node identities. What it does cost is metadata — the hub now knows how many devices an account has and when each last signed in. Also `client.minimum` / `client.recommended` in `GET /v1/hub/version`: an installed client meets a newer hub the day the interface ships in a package, and that is cheap now and awkward to retrofit. Browser ------- The `key_changed` refusal becomes `unknown_device` and offers a linking code instead of telling someone to find their operator. The Members panel lists this account's devices here, approves one by code, and retires one. 773 tests pass. `e2e.py` gained a step that links a device end to end against the live deployment — file, list, recompute, countersign, then open the group with the new keys and no code — and it also gained `recv_type`, because a step that assumes the next message is its own answer reads an ack left by the step before. Co-Authored-By: Claude Opus 5