[release amika] Release amika@v0.14.0

[dbmikus]

Releases the amika CLI at v0.14.0 and rolls that release into the sandbox base image.

Two commits:

1. [release amika] Bump install.sh DEFAULT_VERSION to 0.14.0 — the public CLI release. Carries the Release-Component / Release-Version trailers.
2. Set Amika base snapshot to install amika CLI v0.14.0 and repin amikad — bumps AMIKA_VERSION to 0.14.0 in go/internal/sandbox/presets/base/Dockerfile and repins AMIKAD_SOURCE_REF from 9dccbfd to 4c7b647 (current main).

The amikad repin matters on its own: the old pin predated the no-relay connect-token work, so sandbox images were building an amikad without the connect-token round trip, the sshd-manager fixes, or the state contract additions. The new ref resolves through the module proxy the builder stage's go install uses (github.com/gofixpoint/amika/go v0.0.0-20260810034344-4c7b647bbeb8).

Changes since amika@v0.13.0

Direct (no-relay) SSH transport

• Define and tighten the no-relay SSH contracts and vertical-slice spec (fc01f30, 650b433, dac6b6d)
• Implement the local no-relay SSH path and fix its runtime lifecycle (d4bb156, 05c6df1)
• Add amika scpv2 over the direct WebSocket transport (9dccbfd)
• Bind the managed sshd to a reserved loopback port (2e90dc6)
• Scope v2 SSH session config per control plane (c7063c7)
• Resolve SSH relay review annotations and document the connect-token round trip (Resolve SSH relay review annotations and document the connect-token round trip #322)

SSH key handling

• Harden authorized key handling and close an ownership race (b565213, f448546, 3fde13c)
• Add an amikad authorized-keys clear subcommand (0e2fa59)
• Add the amika secret ssh-key command group (Add the amika secret ssh-key command group #324)

Sandbox images

• Build and package amikad into the base images (6279f28, f336617)
• Repin the reviewed amikad source as fixes landed (862cbbd, 4777f5c, f864496, a6a4c04)
• Add sandbox codev2 editor support (Add sandbox codev2 editor support #325)

Testing and CI

• Test snapshot scrubbing end to end (Test snapshot scrubbing end to end #323)
• Publish linux-vm Daytona snapshots from CI, with retries and paged state verification (930a99f, 5379037, 4e713a7)

Agent tooling

• Add and narrow the amika-cli skill for agents (9b6be25, 8cfc32a)
• Add [release <symbol>] prefix and release trailers to the CLI release skill (59526b2)